Fasting

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Table of Contents Fasting I – A History 1 Fasting II – Fasting Physiology 4 Fasting III – Fasting and Growth Hormone Physiology 7 Fasting IV – Fasting and Lipolysis 10 Fasting V – Fasting Myths 14 Fasting VI – Fasting Regimens 18 Fasting VII – Longer Fasting Regimens 21 Fasting VIII – The Ancient Secret of Weight Loss 24 Fasting IX – Caloric Reduction vs Fasting 26 Fasting X – Women and Fasting 31 Fasting XI – Feasts and Fasts – The Cycle of Life 34 Fasting XII – Practical Fasting Tips 38 Fasting XIII – More Practical Fasting Tips 41 Fasting XIV – The Fasting ‘Advantage’ 45 Fasting XV – Fasting and Muscle Mass 49 Fasting XVI – Fasting Lowers Cholesterol 53 Fasting XVII – Fasting and Hunger 58 Fasting XVIII – Cephalic Phase Response and Hunger 62 Fasting XIX – Circadian Rhythms 65 Fasting XX – Refeeding Syndrome 70 Fasting XXI – Obesity – Solving the Two-Compartment Problem 75 Fasting XXII – The Biggest Loser Diet – Eat Less Move More’s Bigger Brother 80 Fasting XXIII – Fasting and Exercise 84 Fasting XXIV – Fasting and Brain Function 88 Fasting XXV – Fasting and Autophagy 92 Fasting XXVI – Power: Fasting vs Low Carb 95 Fasting XXVII – The Difference Between Calorie Restriction and Fasting 99 Fasting XXVIII – Why You’re Always Hungry 105 Fasting XXIX – Fasting and Ghrelin 108

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Fasting – A History Part I Fasting is a time tested and ancient tradition. It has been used not only for weight loss, but to improve concentration, extend life, prevent Alzheimers, prevent insulin resistance and even reverse the entire aging process. There is much to talk about here so we begin a new subsection “Fasting”.

There is nothing new, except what has been forgotten – Marie Antoinette

So the forgotten question of weight loss is “When should we eat?” We don’t ignore the question of frequency anywhere else. Falling from a building 1000 feet off the ground once will likely kill us. But is this the same as falling from a 1-foot wall 1000 times? Absolutely not. Yet the total distance fallen is still 1000 feet.

All foods will increase insulin levels to some degree. Eating the proper foods will prevent high levels, but won’t do much to lower levels. Some foods that are better than others, but all foods still increase insulin. The key to prevention of resistance is to periodically sustain very low levels of insulin. If all foods raise insulin, then the only answer is the complete voluntary abstinence of food. The answer we are looking for is, in a word, fasting.

Fasting

The answer to this vexing problem lies not in the latest and greatest diet trend, but in the

tried and true. Instead of searching for some exotic, never-before-tried diet miracle, we should focus on ancient healing traditions of the past. The waaaayyyy past. Fasting is one of the most ancient healing traditions in human history. This solution has been practiced by virtually every culture and religion on earth.

Whenever fasting is mentioned, there is always the same eye-rolling response. Starvation? That’s the answer? No. Fasting is completely different beast. Starvation is the involuntary absence of food. It is neither deliberate, nor controlled. Starving people have no idea when and where their next meal will come from. Fasting, on the other hand is the voluntary withholding of food for spiritual, health, or other reasons. It is the difference between suicide and dying of old age. The two terms should never be confused with each other. Fasting may be done for any period of time, from a few hours to months on end. In a sense, fasting is part of everyday life. The term ‘break fast’ is the meal that breaks the fast – which is done daily.

Fasting is one of the most ancient and widespread healing traditions in the world. Hippocrates of Cos (c 460 – c370 BC) is widely considered the father of modern medicine. Among the treatments that he prescribed and championed was the practice of fasting, and the consumption of apple cider vinegar. Hippocrates wrote, “To eat when you are sick, is to feed your illness”.

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The ancient Greek writer and historian Plutarch (cAD46 – c AD 120) also echoed these sentiments. He wrote, “Instead of using medicine, better fast today”. Ancient Greek thinkers Plato and his student Aristotle were also staunch supporters of fasting.

The ancient Greeks believed that medical treatment could be observed from nature. Humans, like most animals, do not eat when they become sick. For this reason, fasting has been called the ‘physician within’. This fasting ‘instinct’ that makes dogs, cats and humans anorexic when sick. This sensation is certainly familiar to everybody. Consider the last time you were sick with the flu. Probably the last thing you wanted to do was eat. So, fasting seems to be a universal human instinct to multiple forms of illnesses. Thus fasting is ingrained into human heritage, and as old as mankind itself.

The ancient Greeks believed that fasting improves cognitive abilities. Think about the last time you ate a huge Thanksgiving meal. Did you feel more energetic and mentally alert afterwards? Or, instead did you feel sleepy and a little dopey? More likely the latter. Blood is shunted to your digestive system to cope with the huge influx of food, leaving less blood going to the brain. Result – food coma.

Other intellectual giants were also great proponents of fasting. Philip Paracelsus, the founder of toxicology and one of three fathers of modern Western medicine (along with Hippocrates and Galen) wrote, “Fasting is the greatest remedy – the physician within”. Benjamin Franklin (1706-1790), one of America’s founding fathers and renowned for wide knowledge in many areas once wrote of fasting “The best of all medicines is resting and fasting”.

Fasting for spiritual purposes is widely practiced, and remains part of virtually every major religion in the world. Jesus Christ, Buddha and the prophet Muhammed all shared a common belief in the healing power of fasting. In spiritual terms, it is often called cleansing or purification, but practically, it amounts to the same thing. The practice of fasting developed independently among different religions and cultures, not as something that was harmful, but something that was deeply, intrinsically beneficial to the human body and spirit. In Buddhism, food is often consumed only in the morning, and followers fast from noon until the next morning daily. In addition to this, there may be various water-only fasts for days or weeks on end. Greek Orthodox Christians may follow various fasts over 180-200 days of the year. Dr. Ancel Keys often considered Crete the poster child of the healthy Mediterranean diet. However, there was a critically important factor that he completely dismissed. Most of the population of Crete followed the Greek Orthodox tradition of fasting.

Muslims fast from sunrise to sunset during the holy month of Ramadan. The prophet Muhammad also encouraged fasting on Mondays and Thursdays of every week. Ramadan is the best studied of the fasting periods. It differs from many fasting protocols in that fluids are also forbidden. In addition to fasting, they also undergo a period of mild dehydration. Further, since eating is permitted before sunrise and after sunset, recent studies (27) indicate that daily caloric intake

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actually rises significantly during this period. Gorging before sunrise and after sunset seems to negate some of the beneficial effect.

So fasting is truly an idea that has withstood the test of time. Arguable, the three most influential people to have ever lived agreed that fasting is beneficial. If this was a harmful practice, do you not think we would have figured this out, oh, say 1000 years ago?

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Fasting Physiology – Part II There are many misconceptions about fasting. It is useful to review the physiology of what happens to our body when we eat nothing.

Physiology

Glucose and fat are the body’s main sources of energy. If glucose is not available, then the body will adjust by using fat, without any detrimental health effects. This is simply a natural part of life. Periods of low food availability have always been a part of human history. Mechanisms have evolved to adapt to this fact of Paleolithic life. The transition from the fed state to the fasted state occurs in several stages.

1. Feeding – During meals, insulin levels are raised. This allows uptake of glucose into tissues such as the muscle or brain to be used directly for energy. Excess glucose is stored as glycogen in the liver.

2. The post-absorptive phase – 6-24 hours after beginning fasting. Insulin levels start to fall. Breakdown of glycogen releases glucose for energy. Glycogen stores last for roughly 24 hours.

3. Gluconeogenesis – 24 hours to 2 days – The liver manufactures new glucose from amino acids in a process called “gluconeogenesis”. Literally, this is translated as “making new glucose”. In non-diabetic persons, glucose levels fall but stay within the normal range.

4. Ketosis – 2-3 days after beginning fasting – The low levels of insulin reached during fasting stimulate lipolysis, the breakdown of fat for energy. The storage form of fat, known as triglycerides, is broken into the glycerol backbone and three fatty acid chains. Glycerol is used for gluconeogenesis. Fatty acids may be used for directly for energy by many tissues in the body, but not the brain. Ketone bodies, capable of crossing the blood-brain barrier, are produced from fatty acids for use by the brain. After four days of fasting, approximately 75% of the energy used by the brain is provided by ketones. The two major types of ketones produced are beta hydroxybutyrate and acetoacetate, which can increase over 70 fold during fasting.

5. Protein conservation phase – >5 days – High levels of growth hormone maintain muscle mass and lean tissues. The energy for maintenance of basal metabolism is almost entirely met by the use of free fatty acids and ketones. Increased norepinephrine (adrenalin) levels prevent the decrease in metabolic rate.

The human body has well developed mechanisms for dealing with periods of low food availability. In essence, what we are describing here is the process of switching from burning glucose (short term) to burning fat (long term). Fat is simply the body’s stored food energy. In times of low food availability, stored food is naturally released to fill the void. So no, the body does not ‘burn muscle’ in an effort to feed itself until all the fat stores are used.

Hormonal Adaptation

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Insulin

Fasting is the most efficient and consistent strategy to decrease insulin levels. This was first noted decades ago, and widely accepted as true. It is quite simple and obvious. All foods raise insulin, so the most effective method of reducing insulin is to avoid all foods. Blood glucose levels remain normal, as the body begins to switch over to burning fat for energy. This effect is seen with fasting periods as short as 24-36 hours. Longer duration fasts reduce insulin even more dramatically. More recently, alternate daily fasting has been studied as an acceptable technique of reducing insulin.

Regular fasting, in addition to lowering insulin levels, has also been shown to improve insulin sensitivity significantly. This is the missing link in the weight loss puzzle. Most diets reduce highly insulin-secreting foods, but do not address the insulin resistance issue. Weight is initially lost, but insulin resistance keeps insulin levels and Body Set Weight high. Fasting is an efficient method of reducing insulin resistance.

Lowering insulin rids the body of excess salt and water. Insulin causes salt and water retention in the kidney. Atkins style diets often cause diuresis, the loss of excess water, leading to the contention that much of the initial weight loss is water. While true, diuresis is beneficial in reducing bloating, and feeling ‘lighter’. Some may also note a slightly lower blood pressure. Fasting has also been noted to have an early period of rapid weight loss. For the first five days, weight loss averages 0.9 kg/ day, far exceeding the caloric restriction and likely due to a diuresis of salt and water.

Growth Hormone

Growth hormone is known to increase the availability and utility of fats for fuel. It also helps to preserve muscle mass and bone density. Secretion is known to be pulsatile, making accurate measurement difficult. Growth hormone secretion decreases steadily with age. One of the most potent stimuli to growth hormone secretion is fasting. Over a five-day fasting period growth hormone secretion more than doubled. The net physiologic effect is to maintain muscle and bone tissue mass over the fasting period.

Electrolytes

Concerns about malnutrition during fasting are misplaced. Insufficient calories are not a major worry, since fat stores are quite ample. The main concern is the development of micronutrient deficiency. However, even prolonged studies of fasting have found no evidence of malnutrition.

Potassium levels may decrease slightly, but even two months of continuous fasting does not decrease levels below 3.0 mEq/L, even without the use of supplements. This duration of fasting is far longer than generally recommended. Magnesium, calcium and phosphorus levels during

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fasting are stable. Presumably, this is due to the large stores of these minerals in the bones. Ninety nine percent of the calcium and phosphorus in the body is stored in the bones. The use of a multi-vitamin supplement will provide the recommended daily allowance of micronutrients. A therapeutic fast of 382 days was maintained with only a multivitamin with no harmful effect on health. Actually, this man maintained that he had felt terrific during this entire period. The only concern may be a slight elevation in uric acid that has been described in fasting .

Adrenalin

Adrenalin levels are increased so that we have plenty of energy to go get more food. For example, 48 hours of fasting produces a 3.6% increase in metabolic rate, not the dreaded metabolic ‘shut-down’. In response to a 4 day fast, resting energy expenditure increased up to 14%. Rather than slowing the metabolism, instead the body revvs it up. Presumably, this is done so that we have energy to go out and find more food.

This is really quite interesting. Fasting, but not low calorie diets results in numerous hormonal adaptations that all appear to be highly beneficial on many levels. In essence, fasting transitions the body from burning sugar to burning fat. Resting metabolism is NOT decreased but instead increased. We are, effectively, feeding our bodies through our own fat. We are ‘eating’ our own fat. This makes total sense. Fat, in essence is stored food. In fact, studies show that the epinephrine (adrenalin) induced fat burning does not depend upon lowering blood sugar.

Fat is food stored away in the long term, like money in the bank. Short term food is stored as glycogen, like money in the wallet. The problem we have, is how to access the money in the bank. As our wallet depletes, we become nervous and go out to fill it again. This prevents us from getting access to money in the bank.

Fat is stored away in the ‘bank’. As our glycogen ‘wallet’ depletes, we get hungry and want to eat. That makes us hungry, despite the fact that there is more than enough ‘food’ stored as fat in the ‘bank’. How do we get to that fat to burn it? Fasting provides an easy way in.

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Fasting and Growth Hormone Physiology – Part 3 HGH is a hormone made by the pituitary gland (the master gland). It plays a huge role in the normal development of children and adolescents as the name implies. However, it also plays a role in adults. HGH deficiency in adults typically leads to higher levels of body fat, lower lean body mass and decreased bone mass (osteopenia).

HGH only lasts a few minutes in the bloodstream. It goes to the liver for metabolism, where it is converted into a number of other growth factors, the most important of which is Insulin Like Growth Factor 1 (IGF1).

Scientists first harvested HGH from cadavers in the 1950s (eeewww), but only synthesized it in labs in the early 1980s. Soon afterwards, it became a popular performance enhancing drug. Normal levels of HGH peak in puberty (as you might expect) and gradually decrease thereafter.

Growth hormone is typically secreted during sleep and is one of the so-called counter-regulatory hormones. HGH along with cortisol and adrenalin tell the body to increase the availability of glucose – so it counters the effect of insulin. High doses of HGH, (or cortisol) will produce higher blood sugars. These hormones are typically secreted in a pulse just before waking (4 am or so) during the ‘counter-reulatory surge’. Remember that all hormones exhibit pulsatile secretion to prevent the development of resistance as we covered in a previous post.

Since HGH typically goes down with age, there may be some benefit to giving HGH for its ‘anti-aging’ effects. Perhaps this decrease in HGH-IGF1 may contribute to the decrease in lean body mass both in lower muscle mass, but also lowered bone mass. So, what are the effects of giving HGH in older people? This was studied in 1990 in a New England Journal of Medicine article.

HGH is difficult to measure since it is pulsatile, so IGF1 can be measured as a surrogate. Healthy men with low IGF1 levels were given HGH for 6 months and the effects measured.

Group 1 is the HGH group and Group 2 is the control group that did not receive HGH. Over 6 months weight overall did not change between the two groups.

But look at the lean body mass. Compared to the control, the HGH group packed on 3.7 kg (8.8%) more lean mass. That’s 8 pounds of lean mass! Fat mass decreased an extra 2.4 kg (5.3 pounds)! Thats a decrease of 14.2%. Even the skin thickness improved. That’s anti-aging, baby!

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In a 2002 JAMA article, similar results were obtained in women as well. There was a decrease in fat mass and an increase in lean mass. Sounds pretty great. So, why aren’t we using it for everybody? Well, there’s a little thing called side effects.

There was an increase in blood sugars. This makes sense, since HGH is a counter-regulatory hormone. Pre-diabetes also significantly increased. There was an increase in fluid retention as well as blood pressure, too. Over the long term, there is also a theoretical risk of increased prostate cancer and heart problems (enlarged heart). So, that’s not very good news.

So artificial injections of HGH are out. What if there is an all-natural method of increasing growth hormone? What about, say, fasting?

In 1982, Kerndt et al published a study of a single patient who decided to undergo a 40 day fast for religious purposes. They

measure numerous metabolic indices over that forty days to see what happened. There is a wealth of data here, but several notable things. Blood pressure slightly decreased. Glucose goes down. From 96 initially, it drops to 56. Insulin goes way, way down. Starting at 13.5, it quickly drops to 2.91 and stays down. That is almost an 80% drop!

Glucagon goes from 139 to a peak of 727 or a 423% increase.

But our concern here is HGH. It starts at 0.73 and peaks at 9.86. That is a 1250% increase in growth hormone. Even with a relatively short 5 day fast, we are talking about 300% increase. All this HGH increases without drugs.

What about the potential side effects? Increased glucose? Nope. Increased blood pressure? Nope. Higher risk of cancer? Nope.

Other studies have shown the same increase in growth hormone. In 1988, Ho KY et al studied fasting and HGH. On the control day, you can see that meals (marked M) very effectively suppress HGH secretion. This is to be expected. Like cortisol, HGH increases glucose and thus is suppressed during feeding. Fasting is a great stimulus.

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During fasting, there is the spike in the early morning, but there is regular secretion throughout the day as well. Hartman et al also showed a 5 fold increase in HGH in response to a 2 day fast.

This HGH is crucial in the maintenance of lean mass – both muscle and bone. One of the major concerns about fasting is the loss of lean mass. This does not occur. In fact, the opposite happens – there is likely an increase in lean mass. Think about this for a second.

Let’s imagine that we are living in Paleolithic times. During the summer of plenty, we eat lots of food and store some of that as fat on our body. Now it is winter, and there is nothing to eat. What do you suppose our body does. Should we start burning our precious muscle while preserving our stored food (fat)? Doesn’t that sound pretty idiotic?

It’s as if you store firewood for a wood-burning oven. You pack lots of firewood away in your storage unit. In fact, you have so much, it is spilling out all over your house and you don’t even have enough room for all the wood you’ve stored. But when the time comes to start up the oven, you immediately chop up your sofa and throw that into the oven. Pretty stupid right? Why would we assume our body is also so stupid?

The logical thing to do is to start burning the stored wood. In the case of the body, we start to burn the stored food (fat stores) instead of burning precious muscle.

This has enormous implications for athletes. While studies are few, it is possible that the elevated HGH stimulated by fasting will increase muscle mass as seen in the earlier studies on HGH administration. This would be an important advantage in elite level athletes, and we are seeing more and more interest in doing this exact sort of protocol.

The recovery from hard workouts would similarly be improved. The increased adrenalin during fasting (to be discussed in future) will also allow you to perform a more intense workout. It will make workouts easier and recovery faster. It is not by accident that many of the early proponents of training in the fasted state are bodybuilders. This is a sport that demands, in particular, high intensity training and extremely low body fat for definition.

So, for all those people who thought that fasting would make you tired, or that you could not exercise during fasting, well, you’re just wrong. Fasting does not ‘burn’ muscle. There is no ‘starvation’ mode from fasting where you shrivel up into the fetal position on your couch.

Rather, fasting has the potential to unleash the anti-aging properties of HGH without any of the problems of excessive HGH (prostate cancer, increased blood sugar, increased blood pressure). For those interested in athletic performance, the benefits are even greater.

So, let’s see. Train harder. Lose Weight. Faster recovery. Decrease insulin and insulin resistance. Decrease sugars. All of these benefits are achieved without drugs, supplements or cost. Yes, like all the best things in life, it’s free. So why is everybody so against it?

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Fasting and Lipolysis – Part 4 Insulin is the main driver of both obesity and type 2 diabetes. The key to reversing both conditions is therefore not “How do we reduce calories?”, but instead “How do we reduce Insulin?” There are almost no drugs that will do this. There is actually two classes of medications that consistently reduces insulin – one by a lot, one by a little. Not by co-incidence, they are the only drugs that consistently reduces weight.

But the problem is that they are both expensive and have side effects. Short of drugs, we need an efficient, effective way to lower insulin if we are to be successful in losing weight. A diet low in refined carbs and sugar will certainly do the trick for some, but for others it is not enough. The answer, if you haven’t guessed yet, is fasting.

The classic descriptions of fasting physiology were written by Dr. George Cahill. We reviewed this in a previous post, but here’s a pictorial version. Essentially, fasting is the gradual shift of burning glucose to burning fat.

In stage 1, most of the body is using exogenous glucose. By stage 2 and 3, glycogen (stored sugar) provides much of the glucose needed. Most tissues are still using sugar, but the liver, muscle and fat cells have started to burn fat.

By stage 4 and 5, glycogen stores have run out. Hepatic and renal (liver and kidney) gluconeogenesis is now providing all the glucose, but only the brain, red blood cells and the renal medulla (the inner part of the kidney) uses glucose. Everything else has shifted over to burning fat. By stage 5, the brain has mostly shifted to burning fat in the form of ketone

bodies. Only a small amount of glucose is needed for red blood cells.

You can see that the origin of the blood glucose gradually switches from exogenous (dietary) to gluconeogenesis made from glycerol. Fat is mostly triglyceride,

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which contains one glycerol backbone and three fatty acids of varying lengths.

Most tissues in the body are able to use fatty acids directly as fuel. By stage 5, only the brain and red blood cells require glucose. So most of the body is now fuelled by fat, not sugar.

You can see the effect of this in the free fatty acid (FFA) concentrations in the blood in response to fasting (also called starvation). The FFA levels in the plasma just skyrocket from almost undetectable. Ketones (to feed the brain) are betahydroxybutyrate and Acetoacetate which also show an increase.

The triglyceride is broken down into the glycerol backbone and the 3 fatty acids. The fatty acids are used directly by the body. The glycerol goes to the liver and is turned into glucose by the process of gluconeogenesis. Therefore, fat is able to provide the necessary small amount of glucose for the brain, red blood cells and renal medulla. You do not need to break down muscle for this.

So, fasting does not really ‘starve’ the muscles of fuel. Instead, scarcely available glucose is replaced with widely available fats as the fuel of choice. That’s good, because the body is able to store virtually unlimited amounts of fat, but only a small amount of glucose. Mother Nature, again, has proven herself far, far smarter than us.

It’s analogous to deciding to switch from hydroelectric power to solar power in the middle of the Sahara desert. Just smart. If there is no glucose, we will burn fat. That’s really good news because if there is anything we really, really want to do is BURN FAT. For all the miracle cures pushed by Dr. Oz that don’t really burn fat, there is one that does – fasting.

We want to burn fat so that we can look like this guy – Brad Pilon (author of authoritative fasting textbook Eat Stop Eat). That’s actually true, even though this is a blatant and transparent ploy to put a picture of the shirtless man to increase female readership. But hey! The internet is a dog eat dog world. Dog, mmmm….

One of the reasons why bodybuilders have a vested interest is that their sport demands extremely low body fat levels combined with high athletic performance.

The brain is now powered mostly on ketones. This is a normal situation. This is the way our body is designed. This should not be confused with diabetic ketoacidosis where excessive ketones are produced in addition to very high glucose levels.

In that situation, there is lots of glucose for the brain to use. However, due to the pathologic lack of insulin, the body also produces lots of ketones. The ketones are not burned for fuel, but instead pile up outside, like unused logs.

Brad Pilon - Poster boy of fasting

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As ketone requirements go up, glucose requirements goes down. In type 1 diabetes, both are very high and this causes a life-threatening problem.

Here’s a question I get sometimes. Can my overweight child fast? Seven hells, no. Here’s a graphical description of why. Children simply may not be able to produce adequate amounts of ketones. Even if they could, I sure as hell would not want to take that risk.

In fact, every major religion in the world requires fasting – but ONLY for adults.

In a more recent study of 4 days of fasting, virtually identical results were found. Let’s take a closer look

There are many interesting details here. First, you will notice that fatty acids increase 373%. Blood glucose drops from 4.9 to 3.5 – lower but still in the normal range, maintained by hepatic gluconeogenesis. Beta

hydroxybutyrate increases 2527% percent! The brain is powered on ketones and the body is powered on fat. That’s the mythical fat burning – Burn, Baby, Burn!

Second, you can see that over 4 days of fasting, there is a continuous increase in norepinephrine, while epinephrine remains relatively stable. The increase in adrenalin increases energy and

prevents the decrease in resting energy expenditure (REE) or metabolism. REE increases more than 10%. There is no metabolic shut-down. Fasting instead revs the body’s metabolism. VO2 also increases slightly indicating a greater capacity of the body for physical exertion.

So here’s a summary so far of what fasting does for the elite athlete, or even the regular person.

1. Train harder – Increased adrenalin, increased VO2

2. Recover faster and build muscle faster – Increased growth hormone.

3. Burn fat – increased fatty acid oxidation.

4. Insulin goes down. This we will consider in more detail later.

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This is all available to every person in the entire world, free of charge. Not only do you NOT have to buy expensive supplements. You will save money because you don’t need to buy food. You will save time because you don’t need to cook or clean up.

If I don’t eat, will I lose weight? Will you lose weight? Well, DUH. If you don’t eat, you will definitely lose weight. So there is no question that this is an effective treatment of weight loss. There are virtually no circumstances where it will not work. Is it unhealthy?

The surprising answer is that fasting is extremely healthy. There are a huge number of incredible benefits to fasting. Train harder, build muscle, burn fat. Love it! All legal and totally free! This is only the beginning – we haven’t even touched on the benefits to obesity, diabetes, cancer, and even the anti-aging effects.

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Fasting Myths – Part 5 Many myths are associated with fasting. These myths have been repeated so often that they are often perceived as infallible truths. Some of the these myths include:

• Fasting puts you in ‘starvation’ mode • Fasting will overwhelm you with

hunger • Fasting causes overeating when you

resume feeding • Fasting will make you lose muscle • Fasting deprives the body of nutrients • Fasting causes hypoglycemia • The brain needs glucose to function • It’s just ‘crazy’

Long ago disproven, nevertheless these myths still persist. If they were true, none of us would be alive today. Consider the consequences of burning muscle for energy. During long winters, there were many days where no food was available. After the first episode, you would be severely weakened. After several repeated episodes, you would be so weak that you would be unable to get hunt or gather food. Humans would never have survived as a species. The better question would be why the human body would store energy as fat if it planned to burn protein instead. The answer, of course, is that is does not burn muscle as we discussed in the previous post. It was only a myth.

There is another persistent myth that brain cells require glucose for proper functioning. This is incorrect. Human brains, unique amongst animals, can use ketones as a major fuel source during prolonged starvation, allowing the conservation of protein such as skeletal muscle. Again, consider the consequences if glucose were absolutely necessary for survival. Humans would not survive as a species. After 24 hours, glucose becomes depleted and we become blubbering idiots as our brains shut down. Our intellect, our only advantage against wild animals, begins to disappear. Humans would have soon become extinct. Fat is simply the body’s way of storing food energy for the long term, and glucose/ glycogen is the short-term solution. When short-term stores are depleted, the body turns to its long-term stores without problems.

Consider an analogy. A freezer stores food in the long term, and a refrigerator used for short-term storage. Suppose that three times a day, everyday, we go to the market to buy food. Some goes into the refrigerator, but the excess goes into the freezer. Soon one freezer is not enough, so we buy another, then another. Over a period of decades, we have ten freezers, and nowhere else to put them. Food in the freezer does not get eaten because three times a day, we still buy more food. There is simply no reason to release the food from the freezer. What would happen if, one day, we decide not to buy food? Would everything shut down in ‘starvation mode’? Nothing could be further from the truth. We would first empty the refrigerator. Then the food, so carefully stored in the freezer would be released.

So, in the body’s case, glucose is used for short-term energy and fat for long-term storage (the freezer). Fat is not burned when plenty of glucose is available. Over decades of abundant

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glucose, fat stores proliferate. What would happen if glucose were suddenly unavailable? Would everything shut down in ‘starvation mode’? Nothing could be further from the truth. Energy, so carefully stored as fat, would be released.

Starvation mode, as it is popularly known, is the mysterious boogieman always raised to scare us away from missing even a single meal. Over one year, approximately 1000 meals are consumed. Over a span of 60 years, this equals 60,000 meals. To think that skipping 3 meals of the 60,000 will somehow cause irreparable harm is simply absurd. Breakdown of muscle tissue happens at extremely low levels of body fat – approximately 4%. This is not something most people need to worry about. At this point, there is no further body fat to be mobilized for energy and lean tissue is consumed. The human body has evolved to survive episodic periods of starvation. Fat is stored energy and muscle is functional tissue. Fat is burned first. This is akin to storing a huge amount of firewood but deciding to burn your sofa instead. It’s stupid. Why would we assume the human body is so stupid? The body preserves muscle mass until the body fat becomes so low that it has no choice.

Studies of alternate daily fasting, for example show that the concern over muscle loss is largely misplaced. Alternate daily fasting over 70 days decreased body weight by 6%, but fat mass decreased by 11.4%. Lean mass (including muscle and bone) did not change at all. Significant improvements were seen in LDL cholesterol and triglyceride levels. Growth hormone increases to maintain muscle mass. Studies of eating a single meal per day found significantly more fat loss despite the same caloric intake. Importantly, no evidence of muscle loss was found.

The other persistent myth of ‘starvation mode’ is that basal metabolism decreases severely and our bodies ‘shut down’. This too is highly disadvantageous to survival of the human species. If, after a single day of fasting, metabolism decreased, then we would have less energy to hunt or gather food. With less energy, we are less likely to get food. So, another day passes, and we are even weaker, making us even less likely to get food. This is a vicious cycle that the human species would not have survived. It’s stupid. Why would we assume the human body is so stupid? There are, in fact, no species of animals, humans included that are evolved to require three meals a day, everyday. We have already seen in a previous post that resting energy expenditure (REE) goes UP, not down during fasting. Metabolism revs up; it does not shut down.

It’s unclear to me where this myth originated. Daily caloric restriction leads to decreased metabolism so people assumed that this would simply be magnified as food intake dropped to zero. This is wrong. If you rely on food for energy, then decreasing food will lead to decreased energy intake, which will be matched by decreased energy expenditure. However, as food intake goes to zero, the body switches energy inputs from food to stored food (fat). This significantly increases the availability of ‘food’ and this is matched by an increase in energy expenditure.

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So what happened in the Minnesota Starvation Experiment? These participants were not fasting. They were eating a reduced calorie diet. The hormonal adaptations to fasting were not allowed to happen. In response to a prolonged period of lowered food intake, the body makes the adjustment to lower TEE.

Everything changes when food intake goes to zero (fasting). The body obviously cannot take TEE down to zero. Instead, the body now switches to burning the fat stored on our bodies. After all, that is precisely, exactly what it was put there for. Our body fat is used for food when no food is available. It’s not put there for looks.

Detailed physiologic measurements show that TEE is maintained or sometimes even increased over the duration of a fast. Alternate daily fasting over 22 days found no measurable decrease in TEE. There was no ‘starvation’ mode. There was no decreased metabolism. Fat oxidation increased 58% while carbohydrate oxidation decreased from 53%. This means that the body has started to switch over from burning sugar to burning fat with no overall drop in energy. Four days of fasting actually increase TEE by 12%. Norepinephrine levels (adrenalin) absolutely skyrocketed 117% to maintain energy. Fatty acids increased over 370% as the body switched to burning fat. Insulin measurements decreased 17%. Blood glucose levels dropped slightly but remained in the normal range.

All the incredibly beneficial adaptations to fasting are not allowed to happen in a low calorie diet.

In fact, look how quickly the merest touch of glucose reverses the hormonal changes of fasting. Only 7.5 grams of glucose (2 teaspoons of sugar or barely a sip of a soft drink) is enough to reverse the ketosis. Almost immediately after consuming glucose, the ketones beta hydroxybutyrate and acetoacetate drop to almost nothing, as does fatty acids. Insulin rises, as does glucose.

What does this mean? The body stops burning fat. It has now returned to burning the sugar that you are eating.

Repeated concerns are raised that fasting may provoke overeating. Studies of caloric intake do show a slight increase at the next meal. After a one day fast, average caloric intake increases from 2436 to 2914. But over the entire 2-day period, there is still a net deficit of 1958 calories.

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The increased calories did not nearly make up for the lack of calories on the fasting day. Personal experience in our clinic shows that appetite tends to decrease with increased duration of fasting.

Does fasting deprive the body of nutrients? Most people have more than ample quantities of nutrients. That’s the whole point. To get rid of some of these nutrients – also known as fat.

If you are worried about micronutrients and minerals – you can always take a general multi-vitamin. A different regimen such as alternate daily fasting (ADF) can also alleviate concerns about nutrient deficiency.

The science is clear. The myths surrounding fasting were only falsehoods.

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Fasting Regimens – Part 6 There are many different fasting regimens. Let’s be very clear to start, though. There is simply no ‘best’ one. They all work to different degrees for different people. Just as some people prefer steak to chicken, there is no right or wrong answer. One regimen will work for one person but be utterly ineffective in the next.

Fasting is defined as the voluntary act of withholding food for a specific period of time. Non-caloric drinks such as water and tea are permitted. An absolute fast refers to the withholding of both food and drink. This may be done for religious purposes, such as during Ramadan in the Muslim tradition, but is not generally recommended for health purposes because of the accompanying dehydration. In our IDM program, we do not ever use the absolute fast. Fasting has no standard duration. Fasts can range from twelve hours to three months or more. You can fast once a week or once a month or once a year. Intermittent fasting involves fasting for shorter periods of time on a regular basis. Shorter fasts are generally done more frequently. Longer fasts are typically twenty-four to thirty-six hours, done two to three times per week. Prolonged fasting may range from one week to one month.

I categorized fasting periods with a break point at 24 hours, although this is somewhat arbitrary. In my experience in the IDM program, I generally use shorter regimens for those who are mostly interested in losing weight without much in the way of type 2 diabetes, fatty liver or other metabolic diseases.

For those who have more significant illnesses, I use longer duration regimens as they tend to give faster results. After the initial ‘breaking’ in period, we always work with the patients to find out what they prefer to do. A surprising number of patients prefer longer duration fasts less frequently.

Short Daily Fasting Regimens

1. 12 hour fasting – There are several regimens of fasting that use a shorter period of fasting but done every day. A 12 hour fasting period done every day used to be ‘normal’. That is, you would eat 3 meals a day from, say 7 am to 7 pm and refrain from eating anything from 7 pm to 7 am.

At that point, you would ‘break your fast’ with a small breakfast. This was pretty standard in the 1950s and 1960s. There wasn’t much obesity back then. However, there were two major changes

that happened since then. First was the change to a higher carbohydrate, lower fat diet. This tended to increase insulin. Second was the increase in meal frequency, as we detail in a previous post, which tended to reduce fasting periods.

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If you could eat unprocessed foods, avoid excessive added sugars, and did not have significant insulin resistance to start, this 12 hr daily fasting was probably good enough for most people to avoid obesity. However, it is not really strong enough to reverse decades of insulin resistance.

2. 16 hour fasting – This regimen involves using a daily 16 hour period of fasting and an 8 hour ‘eating window’. For example, this would mean eating from 11 am – 7 pm, and fasting from 7 pm to 11am. This generally means skipping the morning meal every day. Some people choose to eat 2 meals during that 8 hour window and others will eat 3.

This regimen was popularized by a bodybuilder by the name of Martin Berkhan who blogged about it on his website www.leangains.com, and so the method is sometimes called the LeanGains method. He wrote extensively in the years 2007-2010 but I don’t see much activity on his blog anymore, which is a real shame, because he had some great ideas and original thought. There are still some excellent posts there.

He wrote extensively about training in the fasted state and eating predominantly in the post-workout period. These ideas are supported by the science available (albeit not a lot). However, they do make a lot of common sense.

Several years later, an editor at Men’s Health wrote a book called The 8 hour diet, which essentially used the same 8 hour eating window as the LeanGains method. In his entire book, he strenuously avoided any mention of LeanGains

or Berkhans, even though this method transparently ripped-off LeanGains. You can’t really patent a time period of fasting, but the intellectual dishonestly was appalling, regardless. It is like writing about E=MC2 and never mentioning Albert Einstein, but instead pretending to have ‘discovered’ it yourself.

3. The ‘Warrior’ diet – This was one of the first diets to popularize intermittent fasting regimens. Written by Ori Hofmekler in 2002, this diet stressed that timing of meals mattered almost as much as composition of meals. In other words, ‘when you eat makes what you eat important’. Actually, I think both are important, but the ‘when’ question is seriously under-appreciated, and this book was one of the first to really point this out.

Drawing upon inspiration from ancient warrior tribes such as the Spartans and Romans, the core of the diet consists of eating all meals in the evening during a 4 hour window. The fasting period of 20 hours consisted of most of the day. There was also an emphasis on natural unprocessed foods and high intensity training.

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The main point of all these fasting regimens is the same. It allows the body to lower insulin levels very low for a specified period of time longer than usual. This is precisely what helps to break, or prevent the development of insulin resistance. As we’ve mentioned previously, this is the fundamental biologic principle of homeostasis.

The body likes to maintain everything within a relatively narrow range. Any prolonged stimulus leads to resistance as the body tries to resist the change. In this case, prolonged periods of high insulin will lead to insulin resistance, which will lead back to high insulin levels – in other words, insulin causes insulin resistance.

So, by incorporating daily, or almost daily periods of low insulin, we are able to prevent the development of insulin resistance and even reverse relatively minor levels of resistance. For more established resistance, we would need longer fasting periods – 24 hours or greater.

One of the key advantages of fasting, from a therapeutic standpoint is the lack of upper limit. What this means is that we can continue to apply fasting in an almost unlimited manner with no upper ceiling. The world record for fasting was 382 days, during which the patient suffered no ill effects.

Think about medications for a second. If you take metformin – there is a maximum dose. Same for virtually all meds. Think about low carb or low fat diets – you can only go to zero carbs or fat. There is a maximum dose. That is why insulin is so popular with doctors. You can keep increasing the dose with no ceiling. (As an aside, we recently had a lady taking 400 units of insulin per day in our clinic. Her endocrinologist was happy that her sugars were ‘finally’ controlled. I was appalled.)

Fasting, similarly has no ceiling, which offers much more therapeutic flexibility. In other words, if I can keep applying fasting until I see the desired effect. The dose can go up indefinitely. If you don’t eat, will you lose weight? Of course. So there is almost no question of efficacy. It is only a question of safety and compliance. So for more complicated or serious cases, we can simply increase the dose. We will consider these longer regimens in the next post.

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Longer Fasting Regimens – Part 7 There are several longer duration fasting regimens that are available. I arbitrarily divide it at 24 hours but there is no physiologic reason to do so, other than for classification purposes. There is no magic dividing line. We covered fasting regimens using periods less than 24 hours in our last post. This post will cover those schedules that use fasts longer than 24 hours.

24 hour fasts

This period of fasting is essentially going from dinner to dinner, or breakfast to breakfast, whatever you like. For example, you would eat dinner at 7 pm and then fast until the next day’s dinner at 7 pm. In this regimen, you do not actually go a full day without eating since you are still taking one meal on that ‘fasting’ day.

This is very similar to the ‘Warrior’ style of fasting although that allows a 4 hour eating window so is technically a 20 hour fasting period.

This period of fasting has several important advantages. First, as a longer duration fast, it tends to be a little more effective. Because you still eat every day, medications that need to be taken with food can still be taken. For example, metformin, or iron supplements of aspirin should all be taken with food and can be taken with the one meal on the fasting day.

The other major advantage is that this style is the most easily incorporated into everyday life. Most people, for example will eat dinner with family every single day. As you still eat dinner every day, it is possible to routinely fast for 24 hours without anybody knowing any different, since it really only means skipping breakfast and lunch on that day.

This is particularly easy during a workday. You simply drink your morning cup of joe, but skip breakfast. You work through lunch and get home in time for dinner, again. This saves both time and money. There is no cleanup or cooking for breakfast. You save an hour at lunchtime where

you can work, and be home for dinner without anybody even realizing you had fasted for 24 hrs.

The 5:2 Diet The 5:2 approach is championed by Dr. Michael Mosley, a TV producer and physician best known for popularizing this approach. He appeared on a BBC program called Horizon entitled “Eat, Fast, and Live Longer”.

While there had been some fringe interest being generated by pioneers such as Martin Berkhan and Brad Pilon, they had not really hit the mainstream yet. With the BBC documentary and the book that soon followed, intense interest, especially in the UK followed.

The book, entitled “The Fast Diet” became a best seller in the UK and soon other follow up books were released. The basic diet was not quite a 24 hour fasting period, as Brad Pilon described.

Dr. Michael Mosley

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Instead, the 5:2 diet consisted of 5 days of normal diet. On the other two days, you could eat a total of 500 calories. Those 500 calories could be taken all in a single meal. If, for example, this is taken as dinner, it would be identical to the Eat, Stop, Eat diet. However, you could spread those 500 calories out into multiple meals instead. These two approaches are quite similar and the difference physiologically, is likely quite minimal.

Alternate Daily Fasting (ADF)

This is the dietary strategy that has the most research behind it. Much of it was done by Dr. Krista Varady, an assistant professor of nutrition with the University of Illinois – Chicago. She wrote a book about her strategy in The Every Other Day Diet, although this was not the blockbuster success of the 5:2 diet.

Even though it sounds like you only eat every other day, it is not quite. You can eat up to 500 calories on fasting days, just like in the 5:2 diet. However, fasting days are done on alternate days rather than 2x per week so it is a more intensive regimen. The major advantage of this regimen is that more research is available on this regimen than any other. We will consider these studies in more detail in later posts.

36 hour fasts

As you progressively go longer in fasting, there benefits accrue faster, but there is also more risk of complications. Since I often deal with type 2 diabetics and hard to treat obesity cases, I tend to gravitate towards longer fasting periods, but you must understand that I always monitor very closely their blood pressures, and blood work and progress. I cannot stress enough, that if you do not feel well at any point, you must stop. You can be hungry, but you should not feel sick.

Another major consideration is that medication must be carefully monitored by a physician. The major problem are diabetic medications because if you take the same dose of medication and do not eat, you will become hypoglycaemic and that is very dangerous.

Blood sugars going low is not a complication per se, because that is generally the point of fasting. We want the sugars to go low. However, it does mean that you are overmedicated for that day. You must work very carefully with a physician to adjust medications and monitor sugars. Also, there are certain medications that may cause stomach upset on an empty stomach. NSAIDS, ASA, Iron supplements and metformin are the major drugs here.

In general, diabetic medicates and insulin MUST be reduced on the fasting day to avoid hypoglycaemia. Exactly how much to reduce it should be overseen by your physician.

I DO NOT RECOMMEND ANYBODY WHO IS TAKING ANY MEDICATION TO TRY LONGER FASTS WITHOUT CLEARING IT WITH THEIR DOCTOR.

A 36 hour fast means that you fast one entire day. You finish dinner on day 1 at 7pm for instance, and you would skip all meals on day 2, and not eat again until breakfast at 7 am on day 3. So that is a total of 36 hours of fasting.

42 hour fasts

We often advise our clients to make a routine out of skipping the morning meal and break their fast around noon hour. This makes it easy to follow a 16:8 fasting period on regular days. After a

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few days, most people start to feel quite normal just starting their day with a glass of water and their usual cup of coffee.

When you combine that with a 36 hour fast, you get a 42 hour fasting period. For example, you would eat dinner at 6 pm on day 1. You skip all meals on day 2 and eat your regular ‘break fast’ meal at 12:00. This is a total of 42 hours.

For longer duration fasts, we often try NOT to calorie restrict during that eating period. Often, as people get used to fasting, we hear very often that their appetite starts to seriously go down. Not up. Down. They should eat to satiation on their eating day.

There’s a very good reason for this decrease in appetite. As you start to break the insulin resistance cycle, insulin levels start to decrease. Since insulin is the major regulator of the body set weight (BSW) your body now ‘wants’ to go lower. In response, hunger is suppressed and total energy expenditure is maintained. So – appetite goes down and TEE stays same or goes up. Remember that standard Caloric Reduction as Primary (CRaP) strategies produce the opposite. Appetite goes up and TEE goes down. Which do you think will work in the long run?

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The Ancient Secret of Weight Loss – Fasting Part 8 There really is no upper limit to fasting regimens. Once again, I will add a cautionary note. If you are taking medications or especially if you have diabetes, you need to discuss this with your physician before starting. The blood sugars often come down with fasting regimens, but if you are taking medications, it may come down too low. This is a potentially fatal condition called hypoglycaemia. It often manifests as shaking, sweating and sometimes seizures. Medications often need to be adjusted including blood sugar and blood pressure medications.

Also, if you feel unwell at any point during the fasting, you must stop. You may feel hungry, but you should not feel faint, or unwell or nauseated. This is not normal and you should not attempt to ‘push through’. I am not specifically recommending any fasting regimens, only trying to document various fasting regimens in widespread use.

The world record for fasting is 382 days. This was a 27 year old man in Scotland who fasted in order to lose weight. He weight 456 pounds at the start of the fasting period. During this time, he only took a multi-vitamin, and something called ‘Paladac’ which was vitamin C and yeast. Why on earth anybody decided that eating yeast was that important is really quite beyond me, but hey, this was 1973, when pet rocks and disco was popular, too, so there you go.

He was able to drink as much non-caloric fluids as he wanted. After all, you would only survive less than 3 days without fluids because of significant dehydration. At various periods, he did receive some potassium and sodium supplements, and he was monitored by a physician throughout the fasting

period to see if there was any deleterious effects on his health.

Constipation is one of the main problems we see in fasting. The reason seems simple enough. There is very little going into the gut, so little comes out the other end. This is a problem we face routinely in our IDM clinic. With this world record fast, this patient had bowel movements roughly every 37-48 days. What’s important to note is that this is a normal phenomenon and not an abnormal one. You do not need to have a daily bowel movement to feel well. Nevertheless, less than once a month seems kind of extreme.

His weight decreased from 456 to 180 pounds. Even 5 years afterward, he remained at 196 pounds. One of the most persistent concerns about fasting is the effect on electrolytes. You can see from the accompanying graph that blood sugars do go lower, but remain at the lower limit of normal. There were no episodes of

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hypoglycaemia. This is, of course, to be expected, since the body will begin the process of gluconeogenesis (making of new glucose) in order to supply the brain and certain other parts that need glucose (renal medulla and red blood cells). Even the brain is mostly using ketones at this point. As previously shown, muscle is not consumed to provide glucose (gluconeogenesis). Instead, the glycerol backbone from triglycerides (fat) is recycled into glucose while the three fatty acid chains are used for fuel by most of the body.

Calcium and phosphorus levels in the blood vary over the fasting duration but generally remain within the normal limits and are virtually unchanged by the end of the fast. The same goes for plasma urea and creatinine, which are widely used measures of kidney function. Sodium, potassium, chloride and bicarbonate were all unchanged and in the normal range. In this study, uric acid remains stable although other studies have shown some increased uric acid.

Serum magnesium levels did decrease in this study. This is consistent with what we see clinically in our clinic as well. It seems to be especially prevalent in diabetics. It is important to realize that 99% of the body’s magnesium is intracellular and not measured by blood levels. In this study, researchers took the next step to measure the magnesium content within the cells and the erythrocyte Mg levels remained firmly in the normal range. Nevertheless, we often supplement with magnesium to be on the safe side.

The rate of weight loss was 0.72 pounds per day averaged over the entire 382 days. Other studies of fasting over 200 days had shown similar rates of weight loss (from 0.41 to 0.67 pounds per day) for periods of 210, 236, 249 and 256 days. This average of 0.565 ((0.41 + 0.72)/2) is actually quite interesting.

We assume that one pound of fat is 3500 calories. This is a widely quoted figure, but not especially accurate. If we assume that one eats 2000 calories per day, then we would expect 2000/3500 = 0.57 pounds weight loss per day, which is fairly close to that number actually seen. So, for a patient with 100 pounds of fat to lose, you might expect that it would take roughly 200 days to lose it all. 200 days! I don’t generally subscribe to calorie theory for the reason the Caloric Reduction results in reduced Caloric Expenditure. In other words, decreasing Calories In decreases Calories Out resulting in a plateau of weight loss efforts.

However, in the case of straight-on fasting, the caloric theory holds as promised, resulting in a weight loss very close to that predicted if Caloric Expenditure stays stable. In other words – metabolism does not decrease in fasting. A prolonged caloric reduction, on the other hand, is shown to decrease metabolism.

The Ancient Secret

I’ve sometimes called Intermittent Fasting the ‘Ancient Secret’ of weight loss. Why do I resort to such hyperbole? Well, because it’s true. It is an ancient technique of weight loss – dating at to the time of the ancient Greeks over 2. So, if you want to talk about time-tested practices, nothing beats fasting. Consider that LowCarb diets such as endorsed by William Banting also have a long

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history but only dating from the mid 1800’s. Obesity was quite rare in the time of Jesus Christ, so fasting was used as a method of preserving good health and improving mental clarity.

But why is fasting a ‘secret’? Well, because the nutritional authorities have spent the last 30 years convincing us that we need to eat more to lose weight. We’ve all heard these lies.

You must always eat breakfast within one minute of getting out of bed.

You must eat snacks constantly, all day long or else you’ll be consumed by hunger and stuff your face with Krispy Kreme donuts.

You should eat 6-7 meals a day or else you’ll be consumed by hunger and stuff your face with Krispy Kreme donuts.

You should eat a bedtime snack or else you’ll be hungry while asleep and then stuff your face with Krispy Kreme donuts when you wake up.

You must never, ever miss a meal, otherwise you’ll be consumed by hunger and stuff your face with Krispy Kreme donut.

If you miss a single meal, you’ll develop eating disorders like anorexia. This last one must be one of the most idiotic myths out there. Fasting is not, like, exactly fun. It’s a hell of a long way from morbid obesity to anorexia. Furthermore, anorexia is a psychologic disorder of body image. Fasting does not lead to anorexia any more than washing your hands leads to obsessive compulsive disorder. But these lies persist.

Nevertheless, because of all the worries, you can rest assured that there are studies that show that intermittent fasting does not lead to eating disorders.

Sadly, the public at large has bought into these lies. You can see that from 1977, the vast majority of people ate 3 times a day. By 2003, most people were eating 5-6 times per day. This weight loss advice was as useful as a third nostril.

Much of this increase in eating opportunity is likely to have been funded by Big Food. They want to sell more food. It’s easier to sell more food if people are eating more frequently. So, in order to do that, they needed to make sure that you didn’t ever miss a single meal.

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So here’s the bottom line.

Can you fast? Yes – literally millions of people around the world for thousands of years have done it.

Is it unhealthy? No. In fact, it has enormous health benefits, that we have not even touched upon yet.

Will you lose weight? Here is the crazy thing. People have been convinced that fasting will make them gain weight (the bogeyman – starvation mode). OK, Einstein – if you don’t eat anything for 2 weeks, do you think you will lose weight? Of course.

Is it difficult? Not really. Millions of people do it. But it’s not exactly fun, either.

So fasting is effective, simple (one main rule – don’t eat), flexible (lots of different regimens), practical (saves time and money), and virtually guaranteed to work. So why don’t people support it? Because nobody makes money off you when you fast. Only when you buy crazy things like meal replacement shakes. Nobody wants to you to find out the Ancient Secret of Weight Loss.

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Caloric Reduction vs Fasting – Part 9 Some would argue that the beneficial effect of fasting is due to the caloric reduction. But why is there such a striking difference between reducing calories and fasting? Caloric Reduction as Primary (CRaP) has been tried innumerable times, and failed virtually every single time. Yet fasting is often effective where simple caloric reduction is not. The short answer is that the beneficial hormonal changes that happen during fasting are entirely prevented by the constant intake of food. It is the intermittency of the fasting that makes it so much more effective. This prevents the development of resistance.

Let’s compare the failed CRaP technique to the intermittent fasting (IF) one. Let’s quickly review the conventional advice to portion control, or reduce daily caloric intake. We often hear the advice to simply reduce 500 calories a day and expect to lose 1 pound of fat per week. Success is as rare as humility in a grizzly bear, but that doesn’t stop well meaning, but idiotic health professionals from recommending it. After all, who hasn’t tried to portion control strategy of weight loss. Who has been able to maintain long term weight loss? Does it work? No.

It is always a little surprising to me how fervent the calorie believers are. From a purely practical standpoint, consider this. We, as medical professionals, have advised people for at least 40 years to control their calories. We tell them that is all about Calories In, Calories Out. Technically true, it turns out that the Calories Out, the part we do NOT control is vastly more important than Calories In. Nevertheless, doctors such as Dr. Katz, continue to advise cutting their calories and pretend that they will lose weight.

But it has never worked. The failure rate is 98%. Practical personal experience shows that this is likely to be true. So, whatever else you may believe, caloric reduction DOES NOT WORK. This is a proven fact. Proven in the bitter tears of a million believers. But, no matter how many times I tell a calorie enthusiast, I get the uncomprehending gaze of an anxious monkey. So, what happens with this CRaP strategy? A detailed review can be found in the Calories series earlier. Essentially, the body tends to maintain a body set weight (BSW). The body is initially able to lose some weight. However, as weight goes down, the body compensates for this weight loss by trying to regain the lost weight. Hormonal mediators of hunger (ghrelin) increase. This means that measures of hunger and desire to eat increase. This happens almost immediately and persists almost indefinitely.

Next, the body’s metabolism starts to shut down. In response to a 30% decrease in calories, there is a roughly 30% decrease in total energy expenditure. We start to feel tired, cold, and we have little energy for things like exercise.

As the body’s TEE decreases, the weight loss starts to slow down and then plateau. Eventually the weight starts to go back on, even as we continue to follow the diet. So the metabolic adaptations to CRaP is an increase in hunger and a decrease in basal metabolism. So, as you diet,

Dr. David Katz - Calorie Believer

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you feel hungry, tired, cold and generally miserable. Does this sound familiar to any dieters? Probably sounds familiar to every dieter. This is what Dr. Ancel Keys had shown decades ago in his Minnesota Starvation Experiment.

The worst part is that this strategy is guaranteed to fail. It has been proven by science long ago. The huge 50,000 woman randomized trial (Women’s Health Initiative) of the low fat low calorie diet proved to be an utter failure for weight loss. The problem with this strategy is that it does not address the long term problem of insulin resistance and high insulin levels. Since the insulin sets the ‘BSW thermostat’ – the body keeps trying to regain the lost weight.

Here’s the bottom line. As you reduce calories, appetite goes up, and TEE goes down. You reduce Calories In, but Calories Out goes down, too. This is failure guaranteed 100%. It’s as stupid as cracking the safe of your own bank.

Intermittent Fasting

As we recently detailed in the fasting series, the hormonal changes that happen in IF are completely different. In contrast to CRaP, during fasting, appetite goes down and TEE goes up. The body is trying to lose weight and helping you along. The main point is that it addresses the long term problem of insulin resistance. During caloric reduction alone, you do not get any of the beneficial hormonal adaptations of fasting.

The hormonal adaptations are completely different, as we have discussed so far in this series. Glucose and insulin go down and stay down.

During IF, the intermittent nature of the intervention helps to prevent the insulin resistance problem. A recent trial – The effects of intermittent or continuous energy restriction on weight loss and metabolic disease risk markers: a randomized trial in young overweight women – compares CRaP to IF. In this study, 107 women were randomized to two strategies. The first was a 25% continuous energy restriction (CER) – similar to the CRaP strategy of portion control. The second strategy was intermittent energy restriction (IER). Patients were allowed normal intake on 5 days a week, but only 25% of their usual calories on 2 days of the week – very

similar to the 5:2 diet of Dr. Michael Mosley.

Let’s assume the usual caloric intake was 2000 calories per day. With CER, calories are reduced to 1500, or 10,500 calories over 1 week. With IER, weekly calories are 11,000 calories per week. So this study effectively keeps caloric intake steady – or even favouring the CER group slightly. The basic diet was a Mediterranean style diet with 30% fat.

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Over 6 months, what were the results? In terms of weight loss and fat loss, there were no significant difference although the IER tended to do better (5.7 vs 5.0 kg weight loss, 4.5kg vs 3.2kg fat loss).

But the real important part of the study was the effect on insulin and insulin resistance. After all, I’ve spent the last 60+ blog posts arguing that insulin and insulin resistance are the key factors in obesity and weight gain.

What happens to insulin levels? Well, there is a clear, substantial improvement in insulin levels favouring the IER group. Even more impressive is the change in insulin resistance. This is measured by HOMA, which is a comparison of fasting glucose to fasting insulin.

In the CER group, there is virtually no change in their insulin resistance (IR). Because there is no change in IR, this will continue to lead to higher insulin levels in a vicious cycle. These higher insulin levels perpetuate the higher IR.

This is the long term problem of weight loss. This is exactly the part of the equation that is typically ignored and leads to the typical weight regain. It is the intermittency of the diet that makes it effective.

We can look back at human history. Fasting has been used for the last 2000 years as a tremendously effective method of controlling obesity. Portion control (CRaP) has only been used extensively for the last 50 years with stunning failure. Yet, pundits such as Dr. Katz and others continually scream at us through books, TV, and online to reduce calories. Don’t they think we’ve tried that?

But the one strategy that does help, fasting, is continually belittled as a dangerous practice akin to blood letting and voodoo. The problem with most diets is that they ignore the biological principle of homeostasis – that is the ability of the body to adapt to changing environments. The body has a preferred state. If you move away from it, the body will adapt to it. For example, if you are in a dark room and suddenly go into the bright sunlight, you will momentarily be blinded. However, within moments, your body will adapt.

The same applies to weight loss. If you try to keep a constant diet, the body will adapt to it. This means that successfully dieting requires an intermittent strategy, not a constant one. This is a crucial difference.

The difference is between restricting some foods all the time (CER) and restricting all foods some of the time (IER). This is the difference between failure and success.

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Women and Fasting – Part 10 Not surprisingly, the use of fasting for weight loss has a long history, since it’s, kind of, like, obvious. I mean, everybody understands that if you do not eat, you are highly likely to lose weight. Duh. Which makes it even more surprising how much people fear missing even a single meal, let alone fast for a prolonged period of time. They think that fasting (not eating) will make you fat. That’s kind of like saying that splashing water on your head will dry your hair. That’s modern dietetics for you. Kind of a Bizarro world.

There are still many doctors who argue that eating sugar is not bad for type 2 diabetics. Kind of makes you wonder how they got into medical school at all. Since it is quite obvious that missing meals leads to weight gain, the old bogeyman, ‘starvation mode’ is often invoked to instill fear. Tales of people ‘ruining’ their metabolism abound. Food companies, of course have eagerly ‘educated’ medical professionals about the dangers of missing meals and the safety of eating sugar. Nobody makes money when you skip meals.

Fasting appeared in the medical literature over 1 century ago. Interestingly, they describe ‘professional fasters‘ who would fast for specific periods of time for exhibition. One professional faster went for 30 days and drank a quantity of his own urine. Talk about being starved for entertainment. Kind of like watching paint dry. This was depicted in Franz Kafka’s short story “A Hunger Artist”. Fasting for entertainment was popular from 1883-1924. My guess is that it really is not that entertaining.

In the early 1900s, Drs. Folin and Denis described fasting as ‘a safe, harmless and effective method for reducing weight of those suffering from obesity’. Great. That’s exactly what we need. Something safe, harmless, and effective. The fact that fasting has been performed (mostly for religious purposes) for several thousand years only reinforced the long history of safety. It’s hard to argue that fasting is dangerous if people have been doing for the 5000 years. May as well argue that using soap is dangerous. Yet, myths about the dangers of fasting are everywhere.

By the early 1950’s, Dr. W. Bloom reignited interest in fasting as a therapeutic measure mostly using shorter fasting periods. However, many longer periods were also described in the literature. Dr. Gilliland reviewed fasting in the revival of the 1950’s and1960’s and reported his experience with 46 patients “whose reducing regime started with a standard absolute fast for 14 days”. Whoa. I love that. When I tell people to fast for more than 24 hours their eyes just about bug out of their head. These people had a ‘standard’ fast that lasted for 2 weeks! And that was just the beginning!

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Of these, there were 14 males and 32 females. This is important because I constantly get questions about whether fasting works for females. This is primarily, I think due to a post found online that’s been viewed close to 100,000 times. What she wrote in 2012 is this – “Intermittent fasting and women: Should women fast? The few studies that exist point towards no.”

Nothing is further from the truth. There are hundreds of studies spanning over 100 years and clinical experience spanning 5000 years that point to the fact that women and men respond more or less equally except in the underweight situation. This is an easy problem. Should anybody who is seriously underweight, fast? Uh, no. You don’t have to be a genius to figure that out yourself. If you are severely underweight and fast, you could become infertile, yes.

Consider the past 2000 years of human history. Are Muslim women ‘exempt’ from fasting? Are Buddhist women ‘exempt’ from fasting. Are Catholic women ‘exempt’ from fasting? So we have millions of person-years of practical experience with women and fasting. And there are no problems in 99.9% of cases. In our own clinic, where we’ve treated close to 1000 patients, I have noticed no significant difference between men and women. If anything, the women tend to do better. Men, it seems, are sometimes just big babies. I will mention here, too, that the highest success rates come when husband and wife do it together.

However, pregnant women are, in fact ‘exempt’ from fasting in almost all human religion. As are children. In both situations, this makes entirely logical sense. These people need adequate nutrients for growth, and human populations have always acknowledged this.

Let’s be clear here. This point is made that several problems come up with fasting in women. Well, they come up with men and fasting, too. Sometimes women don’t lose weight the way they want. Well, that happens with men, too. The problem of amenorrhea arises when body fat is too low. Yeah, that’s not a problem we treat with fasting. If amenorrhea or any other problems appear during fasting – stop immediately. The women and fasting issue is just another myth designed to discourage fasting. Virtually all case series of the past 100 years have included both

men and women.

Anyway, back to the study. The patients were hospitalized into a metabolic ward during the first 14 days and only water, tea and coffee were allowed. After that, they were discharged and asked to follow a 600-1000 calorie diet. Funny enough, 2 patients asked(!) to be readmitted for a second 14 day period of fasting because they wanted better results. Did it work? Was there ever any doubt?

Average weight loss was 17.2 pounds in 14 days. This is in excess of the roughly 1/2 pound per day of fat loss seen in more prolonged fasting. This indicates that some of the initial early weight loss is water

weight. This is confirmed by the rapid regain of weight upon refeeding. It is important to understand this in order to avoid the disappointment that often accompanies the weight

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gain upon eating again. That quick weight loss and regain is water weight and not a reflection that the fasting ‘failed’. 44 of 46 patients completed the 2 week fasting period. One developed nausea and one simply decided against it and dropped out.

That’s a 96% success rate even for a regimen as long as a 2 week fast! This is our clinical experience as well. People always think they cannot do it without ever having tried it a single time. Once we start with fasting, patents in our Intensive Dietary Management (IDM) program quickly realize that it’s actually quite easy.

However, after the fasting period, patients were instructed to go on a low calorie diet. This was terribly unsuccessful. 50% of patients did not adhere to this diet over the ensuing 2 year follow up period. Instead of applying successful intermittent techniques, they returned to the unsuccessful constant energy restriction we discussed at the last post.

The key point here is that the natural rhythm of life is Feast and Fast. There are times that you should feast (weddings, celebrations), and there are times that you should fast. Intermittent. To constantly restrict calories for years on end is unnatural and ultimately worse, unsuccessful.

Ketones appeared in the urine starting on day 2 and persisted throughout the fasting period. All 3 diabetic patients were all off insulin by the end of the 2 weeks. One patient with severe congestive heart failure was able to walk without breathlessness by the end. This 2 week fast was not harmful, as we have been told, but extremely beneficial.

Was it hard? In fact, Dr. Gilliland describes a ‘feeling of well being’ and ‘euphoria’. Hungry? Well, no. “We did not encounter complaints of hunger after the first day. We did not meet anorexia.” These experiences were echoed by other researchers of the time.

Dr. Drenick, from the VA centre in Los Angeles, also wrote extensively about therapeutic fasting. His experience was published in 1968. This was a time of renewal of interest in fasting for weight loss. He published his experience of 6 men and 4 women (yes, again there were women in the study). Did it work? In a word, yes.

Should women fast? Yes

Should men fast? Yes

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Feasts and Fasts – The Cycle of Life – Fasting part 11 Feasts are an important part of life. This is a vitally important fact to acknowledge. That is, every single important celebration is marked by feasting. Eating is a celebration of life. Any diet that does not acknowledge this fact is doomed to failure. We eat cake on our birthday. We eat holiday feasts like Thanksgiving. We celebrate Christmas dinner. We prepare wedding banquets. We go to a nice restaurant on our anniversary.

We don’t celebrate with birthday salad. We don’t prepare wedding meal replacement bars. We don’t eat Thanksgiving ‘green’ shakes. We need to acknowledge a fact that we’ve known all along. Weight gain is not a constant phenomenon. It’s an intermittent one. With that knowledge, you can see that a lasting solution to weight gain is also intermittent. Weight gain varies throughout life, and also throughout the year.

Certain periods of life are associated with increased weight gain. This includes adolescence, where weight gain is part of normal development. This also includes pregnancy, another situation where insulin plays a dominant role. Weight gain during pregnancy is normal. However, it also increases the risk of obesity later in life as well – a demonstration of the time dependence of insulin and obesity. This period of increased insulin effect (to help the body gain weight) may have lasting effects.

The simplest way to study this question is to compare women who have had children with those who have not. There are multiple problems with this approach since this is not a randomized group, and those who have never had children (nulliparous) may differ from those who have had children. For example, the stress of having children and associated sleep deprivation may have an effect. However, a randomized study is out of the question, so this is the best data we will get.

10 year follow up data from the first National Health and Nutrition Examination Survey (NHANES 1971-75) was used in this paper from 1994. Overall, the women’s weight gain in those with children compared to nulliparous was 1.6 kg after adjustment. With 1, 2, and 3 children the weight gain averaged 1.7kg, 1.7kg, and 2.2 kg respectively, so there shows some evidence of dose-response.

That doesn’t seem so bad, does it? But the risk of gaining more than 13 kg was increased by 40-60%! The risk of becoming overweight was increased by 60-110%. So, while the overall effect seems modest, the health consequences may not be so. There seem to be some who are predisposed to gain large amounts of weight with childbirth and many who go back to the pre-birth weights. You probably already know some.

This is far from an isolated finding. In 1994, the Journal of the American Medical Association published the CARDIA study also showed a 2-3 kg weight gain over 5 years associated with

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pregnancy. This happened in both blacks and whites. Waist to hip ratio also increased – an indicator of visceral fat gain – the more dangerous type.

Menopause is also associated with significant weight gain. Women were measured during their menopausal years and averaged 2.25 kg weight gain average. Along with this, the blood pressure, serum cholesterol and fasting insulin tends to increase. In men, weight tends to increase in the years after marriage. Married men tend to be fatter than unmarried ones. This does not seem to hold true for women.

The main point is this – weight gain is not always steady. Also weight gain is largely a hormonal, not a caloric imbalance. The hormonal changes of pregnancy and menopause can certainly precipitate large weight changes. Trying to battle a hormonal problem with calorie-based weapons is a losing proposition.

Other life events often cause or are associated with weight gain. Smoking cessation is a major cause of weight gain. In a NEJM paper in 1991, it was estimated that weight gains average 2.8 kg in men and 3.8 kg in women. However, some people have major weight gains of >13 kg – 9.8% in men and 13.4% in women.

Even with a single year, the majority of weight gain happens in a short period of time. Let’s take a closer look at where weight gain happens in a paper published in the New England Journal of Medicine in 2000 called “A prospective study of holiday weight gain“. The holiday period of US Thanksgiving to New Years covers roughly 6 weeks. Researchers repeatedly measured a sample of 200 US adults to see whether weight gain happened disproportionately during this time.

Average weight gain over the entire year averages 0.2-0.8 kg per year. This is close to the 1-2 pound per year average that is commonly quoted in the lay press. In this study the average weight gain over the entire year was 0.62kg.

However, this weight gain is not equally gained throughout the year. In the 6 weeks of the holiday period, roughly 2/3 of the weight of the entire year was gained (0.37 kg). In the remaining 46 weeks of the year, only 1/3 of the weight is gained. There is a small attempt to lose weight in the immediate post-holiday period, but this is clearly not sufficient to offset the holiday weight gain.

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Another interesting finding was that those subjects who were already overweight or obese tended to gain the most weight during the holiday period. This is probably not news to people. The fat get fatter. Those who have struggled with weight for the longest, have the most trouble.

This is yet another example of the time-dependency of obesity. One of the major shortcomings of the caloric theory is the overlooking of this important fact of life.

If weight gain is not uniform throughout the year, then weight loss efforts also need to vary. You need a strategy of increasing weight loss at times and maintenance of weight at others. A constant diet does not match the cycle of life. Feast and Fast. There are times that you should eat a lot. There will be other times that you should be eating almost nothing. That is the natural cycle of life.

If we keep all the feasting, but eliminate all the fasting, then it is rather predictable what the result is. Weight gain. In fact, religions have almost universally acknowledged this fact. There are many periods where feasting is prescribed – Christmas for example. There are other periods of time where fasting is prescribed – Lent, for example.

The ancient civilizations and religions all knew this simple rhythm of life. When the harvest comes in, you feast. But you will fast often in the upcoming winter. But now, in our modern day of continuous food availability, religions have prescribed periods of feasting and fasting. We have kept the feasts, but fear the fasts. They have become demonized. And we have paid the price.

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Type 2 diabetes has become an absolute epidemic in all age groups. It seems pretty obvious that this is a balance problem. If you feast, you must fast. If you keep all the feasting and lose all the fasting, you get fat. That’s really not so hard to understand, is it?

But what happens when you lose all the feasting? Well, then life becomes a little less special. If you are the guy at the wedding who won’t drink, who won’t eat the cake, who won’t eat the full meal, who won’t eat the appetizers – there’s a name for that – the party pooper.

Maybe you can keep it up for 6 months, or 12 months. But forever? Heck, not even the most extreme religions did that. That’s pretty hard to do. Life is full of ups and downs. Celebrate the ups because the downs are right around the corner. But you must balance the periods of eating a lot with periods of eating very little. It’s all a matter of balance

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Practical Fasting Tips – Part 12 We’ve dealt extensively with the science of fasting, but sometimes there are many practical considerations that need exploring, too. Fasting, like anything else in life requires some practice. In days past, when religious fasting was a communal practice, these sort of practical tips were passed on from generation to generation. If not, friends would often have useful advice on how to handle the fasting, because there are definitely some problems that commonly arise. However, with the decline in the practice of fasting, these sorts of advice are often difficult to find.

What can I take on fasting days?

There are many different rules for fasting. During Ramadan, for example, fasting is practiced from sunrise to sundown and no food or beverages are taken. Other types of fasting will only restrict certain types of foods – for example, abstaining from meat for a day. So there are no right or wrong rules. What I describe is the fasting that we prescribe for health and weight loss, as we use in our Intensive Dietary Management program.

All calorie-containing foods and beverages are withheld during fasting. Be sure to stay well hydrated throughout your fast. Water, both still and sparkling, is always a good choice. Aim to drink two liters of water daily. As a good practice, start every day with eight ounces of cool water to ensure adequate hydration as the day begins. Add a squeeze of lemon or lime to flavor the water, if you wish. Alternatively, you can add some slices of orange or cucumber to a pitcher of water for an infusion of flavor, and then enjoy the water throughout the day. You can dilute apple-cider vinegar in water and then drink it, which may help with your blood sugars. However, artificial flavors or sweeteners are prohibited. Kool-Aid, Crystal Light, or Tang should not be added to the water.

All types of tea are excellent, including green, black, oolong and herbal. Teas can often be blended together for variety, and can be enjoyed hot or cold. You can use spices such as cinnamon or nutmeg to add flavor to your tea. Adding a small amount of cream of milk is also acceptable. Sugar, artificial sweeteners or flavors are not allowed. Green tea is an especially good choice here. The catechins in green tea are believed to help suppress appetite.

Coffee, caffeinated or decaffeinated, is also permitted. A small amount of cream or milk is

acceptable, although these do contain some calories. Spices such as cinnamon may be added, but not sweeteners, sugar or artificial flavors. On hot days, iced coffee is a great choice. Coffee has many health benefits, as previously detailed.

Homemade bone broth, made from beef, pork, chicken or fish bones, is a good choice for fasting days. Vegetable broth is a suitable alternative, although bone broth contains more nutrients. Adding a good pinch of sea salt to the broth will help you stay hydrated. The other fluids—coffee, tea, and water—do not contain sodium, so during longer fasting periods, it is possible to become salt-depleted. Although many fear the added sodium, there is far greater danger in

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becoming salt depleted. For shorter fasts such as the twenty-four- and thirty-six-hour variety, it probably makes little difference. All vegetables, herbs or spices are great additions to broth, but do not add bouillon cubes, which are full of artificial flavors and monosodium glutamate. Beware of canned broths: they are poor imitations of the homemade kinds. (See below for a bone-broth recipe.)

Broth Recipe

Vegetables

Chicken, pork or beef bones

1 tbsp of vinegar

Sea salt, to taste

Pepper, to taste

Ginger, to taste

1. Water to cover 2. Simmer for two to three hours until

ready 3. Strain and de-fat

How do I break my fast?

Be careful to break your fast gently. There is a natural tendency to eat large amounts of food as soon as the fast is over. Interestingly, most people don’t actually describe overwhelming hunger, but more of a psychological need to eat. Overeating right after fasting may lead to stomach discomfort. While not serious, it can be quite uncomfortable. This problem tends to be self-correcting.

Try breaking your fast with a handful of nuts or a small salad to start. Then wait for 15-30 minutes. This will usually give time for any waves of hunger to pass, and allow you to gradually adjust. Short duration fasts (24 hours or less) generally require no special breaking of the fast, but certainly for longer fasts it is a good idea to plan ahead.

I get hungry when I fast. What can I do?

This is probably the number-one concern. People assume they’ll be overwhelmed with hunger and unable to control themselves. The truth is that hunger does not persist, but instead comes in waves. If you’re experiencing hunger, it will pass. Staying busy during a fast day is often helpful. Fasting during a busy day at work keeps your mind off eating.

As the body becomes accustomed to fasting, it starts to burn its stores of fat, and your hunger will be suppressed. Many people note that as they fast, appetite does not increase but rather starts to decrease. During longer fasts, many people notice that their hunger completely disappears by the second or third day.

There are also natural products that can help suppress hunger. Here are my top five natural appetite suppressants:

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1. Water: As mentioned before, start your day with a full glass of cold water. Staying hydrated helps prevent hunger. (Drinking a glass of water prior to a meal may also reduce hunger.) Sparkling mineral water may help for noisy stomachs and cramping.

2. Green tea: Full of anti-oxidants and polyphenols, green tea is a great aid for dieters. The powerful anti-oxidants may help stimulate metabolism and weight loss.

3. Cinnamon: Cinnamon has been shown to slow gastric emptying and may help suppress hunger.(1) It may also help lower blood sugars and therefore useful in weight loss. Cinnamon may be added to all teas and coffees for a delicious change.

4. Coffee: While many assume that caffeine suppresses hunger, studies show that this effect is likely related to anti-oxidants. Both decaffeinated and regular coffee shows greater hunger suppression than caffeine in water.(2) Given its health benefits (see chapter 21 [REF.]), there is no reason to limit coffee intake. The caffeine in coffee may also raise your metabolism further boosting fat burning.

5. Chia Seeds: Chia seeds are high in soluble fiber and omega 3 fatty acids. These seeds absorb water and form a gel when soaked in liquid for thirty minutes, which may aid in appetite suppression. They can be eaten dry or made into a gel or pudding.

Can I exercise while fasting?

Absolutely. There is no reason to stop your exercise routine. All types of exercise, including resistance (weights) and cardio, are encouraged. There is a common misperception that eating is necessary to supply “energy” to the working body. That’s not true. The liver supplies energy via gluconeogenesis. During longer fasting periods, the muscles are able to use fatty acids directly for energy.

As your adrenalin levels will be higher, fasting is an ideal time to exercise. The rise in growth hormone that comes with fasting may also promote muscle growth. These advantages have led many, especially those within the bodybuilding community, to take a greater interest in deliberately exercising in the fasted state. Diabetics on medication, however, must take special precautions because they may experience low blood sugars during exercise and fasting. (See “What if I have diabetes?” for recommendations, in next post.)

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More Practical Fasting Tips – part 13 Will fasting make me tired?

In our experience at the Intensive Dietary Management Clinic, the opposite is true. Many people find that they have more energy during a fast—probably due to increased adrenalin. Basal metabolism does not fall during fasting but rises instead. You’ll find you can perform all the normal activities of daily living. Persistent fatigue is not a normal part of fasting. If you

experience excessive fatigue, you should stop fasting immediately and seek medical advice.

Will fasting make me confused or forgetful?

No. You should not experience any decrease in memory or concentration. The ancient Greeks believed that fasting significantly improved cognitive abilities, helping the great thinkers attain more clarity and mental acuity. Over the long term, fasting may actually help improve memory. One theory is that fasting activates a form of cellular cleansing called autophagy that may help prevent age-associated memory loss.

I get dizzy when I fast. What can I do?

Most likely, you’re becoming dehydrated. Preventing this requires both salt and water. Be sure to drink plenty of fluids. However, the low-salt intake on fasting days may cause some dizziness. Extra sea salt in broth or mineral water often helps alleviate the dizziness.

Another possibility is that your blood pressure is too low—particularly if you’re taking medications for hypertension. Speak to your physician about adjusting your medications.

I get headaches when I fast. What can I do?

As above, try increasing your salt intake. Headaches are quite common the first few times you try a fast. It is believed that they’re caused by the transition from a relatively high-salt diet to very low salt intake on fasting days. Headaches are usually temporary, and as you become accustomed to fasting, this problem often resolves itself. In the meantime, take some extra salt in the form of broth or

mineral water.

My stomach is always growling. What can I do?

Try drinking some mineral water.

Since I’ve started fasting, I experience constipation. What can I do?

Increasing your intake of fiber, fruits and vegetables during the non-fasting period may help with constipation.

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Metamucil can also be taken to increase fiber and stool bulk. If this problem continues, ask your doctor to consider prescribing a laxative.

I get heartburn. What can I do?

Avoid taking large meals. You may find you have a tendency to overeat once you finish a fast, but try to just eat normally. Breaking a fast is best done slowly. Avoid lying down immediately after a meal and try to stay in an upright position for at least one-half hour after meals. Placing wooden blocks under the head of your bed to raise it may help with night-time symptoms. If none of these options work for you, consult your physician.

I take medications with food. What can I do during fasting?

There are certain medications that may cause problems on an empty stomach. Aspirin can cause stomach upset or even ulcers. Iron supplements may cause nausea and vomiting. Metformin, used for diabetes, may cause nausea or diarrhea. Please discuss whether or not these medications need to be continued with your physician. Also, you can try taking your medications with a small serving of leafy greens.

Blood pressure can sometimes become low during a fast. If you take blood-pressure medications, you may find your blood pressure becomes too low, which can cause light-headedness. Consult with your physician about adjusting your medications.

I get muscle cramps. What can I do?

Low magnesium levels, particularly common in diabetics, may cause muscle cramps. You may take an over-the-counter magnesium supplement. You may also soak in Epsom salts, which are magnesium salts. Add a cup to a warm bath and soak in it for half and hour. The magnesium will absorb through your skin.

What if I have diabetes?

Special care must be taken if you are diabetic or are taking diabetic medications. (Certain diabetic medications, such as metformin, are used for other conditions such as polycystic ovarian syndrome.) Monitor your blood sugars closely and adjust your medications accordingly. Close medical follow-up by your physician is mandatory. If you cannot be followed closely, do not fast.

Fasting reduces blood sugars. If you are taking diabetic medications, or especially insulin, your blood sugars may become extremely low, which can be a life-threatening situation. You must take some sugar or juice to bring your sugars back to normal, even if it means you must stop your fast for that day. Close monitoring of your blood sugars is mandatory.

Low blood sugar is expected during fasting, so your dose of diabetic medication or insulin may need to be reduced. If you have repeated low blood sugars it means that you are over-medicated, not that the fasting process is not working. In the Intensive Dietary Management Program, we often reduce medications before starting a fast in anticipation of lower blood sugars. Since the blood sugar response is unpredictable, close monitoring with a physician is essential.

Monitoring

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Close monitoring is essential for all patients, but especially, for diabetics. You should also monitor your blood pressure regularly, preferably weekly. Be sure to discuss routine blood work, including electrolyte measurement, with your physician. Should you feel unwell for any reason, stop your fast immediately and seek medical advice. In addition, diabetics should monitor their blood sugars a minimum of twice daily and recorded.

In particular, persistent nausea, vomiting, dizziness, fatigue, high or low blood sugars or lethargy are not normal with intermittent or continuous fasting. Hunger and constipation are normal symptoms and can be managed.

Top 8 Intermittent Fasting tips

1. Drink water: Start each morning with a full eight-ounce glass of water. 2. Stay busy: It’ll keep your mind off food. It often helps to choose a busy day at work for a fast day. 3. Drink coffee: Coffee is a mild appetite suppressant. Green tea, black tea, and bone broth may also help. 4. Ride the waves: Hunger comes in wave; it is not continuous. When it hits, slowly drink a glass of water or a hot cup of coffee. Often by the time you’ve finished, your hunger will have passed. 5. Don’t tell anybody you are fasting: Most people will try to discourage you, as they do not understand the benefits. A close-knit support group is often beneficial, but telling everybody you know is not a good idea. 6. Give yourself one month: It takes time for your body to get used to fasting. The first few times you fast may be difficult, so be prepared. Don’t be discouraged. It will get easier. 7. Follow a nutritious diet on non-fast days: Intermittent fasting is not an excuse to eat whatever you like. During non-fasting days, stick to a nutritious diet low in sugars and refined carbohydrates. 8. Don’t’ binge: After fasting, pretend it never happened. Eat normally, as if you had never fasted.

The last and most important tip is to fit fasting into your own life! Do not limit yourself socially because you’re fasting. Arrange your fasting schedule so that it fits in with your lifestyle. There will be times during which it’s impossible to fast: vacation, holidays, weddings. Do not try to force fasting into these celebrations. These occasions are times to relax and enjoy. Afterwards, however, you can simply increase your fasting to compensate. Or just resume your regular fasting schedule. Adjust your fasting schedule to what makes sense for your lifestyle.

What to expect

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The amount of weight lost varies tremendously from person to person. The longer that you have struggled with obesity, the more difficult you’ll find it to lose weight. Certain medications may make it hard to lose weight. You must simply persist and be patient.

You’ll probably eventually experience a weight-loss plateau. Changing either your fasting or dietary regimen, or both, may help. Some patients increase fasting from twenty-four-hour periods to thirty-six-hour periods, or try a forty-eight-hour fast. Some may try eating only once a day, every day. Others may try a continuous fast for an entire week. Changing the fasting protocol is often what’s required to break through a plateau.

Fasting is no different than any other skill in life. Practice and support are essential to performing it well. Although it has been a part of human culture forever, many people in North America have never fasted in their lives. Therefore, fasting has been feared and rejected by mainstream nutritional authorities as difficult and dangerous. The truth, in fact, is radically different.

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The Fasting ‘Advantage’ – Part 14 What is the advantage of using a strategy based on intermittent fasting versus simple dietary changes alone – such as the LowCarb HighFat diets that we prefer? There are several good ones.

Reason #1 – Simplicity

Simplicity.

When I started out my clinic, I tried to persuade people to adopt the LCHF diet. I was doing this for people of all ages, of all nationalities. It is difficult enough for a well educated English speaking, computer literate person to adopt a strict LCHF diet. This is hard given all the conflicting advice flying around the internet and the airwaves.

We would tell people to go Low Carb and find food diaries full of whole wheat bread and plates of pasta. Many people honestly did not understand the diet at all. I spent lots of time and grey hair trying to change their diets, but many people simply did not understand. Furthermore, their diets had not significantly changed in 40 years, and they were having a lot of trouble changing it.

Since the Low Fat approach had been indoctrinated into them for the last 20 years, it was hard for people to understand how to eat a diet high in natural fats, rather than the low fat fare they were used to. Using a completely different approach such as fasting was much easier for people to understand.

Fasting itself, is so simple that it can be explained in two sentences. Eat nothing including sugars or sweeteners. Drink water, tea, coffee or bone broth. That’s it. Even with this simple method, we (Megan, not actually me anymore) spend hours explaining ‘how to’ fast.

The most obvious benefit to simplicity, though is demonstrated by the startlingly simple graph above. The simpler, the more effective. Amen.

Reason #2 – Cheap

While I may prefer patients to eat organic, local grass fed beef and avoid the white bread and processed foods, the truth is that these foods are often 10 times the cost. Some people, simply put, cannot afford to eat that well.

This is due to the distorting effect of government subsidies on cost of food. Since grains enjoy substantial government subsidies, it is far cheaper to make something out of

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flour than whole foods. This means that fresh cherries cost $6.99/ pound and an entire loaf of bread will cost $1.99. Feeding a family on a budget is a lot easier when you buy pasta and white bread.

But that does not mean they should be doomed to a lifetime of type 2 diabetes and disability. Fasting is free. Actually, it is not simply free, but it actually saves people money because you do not need to buy any food.

Reason #3 – Convenience

While I may advise people to always eat a home cooked, prepared-from-scratch meal, there are many people who simply do not have the time or inclination to do so. The number of meals eaten away from home has been increasing over the past few decades. While there are many who try to support the ‘slow food’ movement, it is clear that they are fighting a losing battle.

Don’t get me wrong, I love cooking as much as the next guy. But it just takes a lot of time. Between work, writing, and taking my kids to school stuff and hockey, it just doesn’t leave a lot of time.

So asking people to devote themselves to home cooking, as noble as it may be, is not going to be a winning strategy. Fasting, on the other hand is the opposite. You save time because there is no time spent buying food, preparing, cooking and cleaning up. It is a way to simplify your life. I often skip breakfast in the mornings. Man, the time saved! I often skip lunch, too. Man, the time saved! If time is money….

Reason #4 – Cheat days

While I might advise people to never, ever again eat ice cream, I don’t think that is actually very practical advice. Sure, you might be able to swear off of it for 6 months, or 1 year, but for life? And would you really want to? Think about it. Think about the joy that some people get from savouring an especially delicious dessert at a wedding feast. Do we need to deny ourselves that little bit of pleasure forever? Let us all enjoy our birthday salad feast! Thanksgiving kale festival! All you can eat brussel sprouts! Yes, life just got a little less sparkly. Forever is a long time.

Now, I am not saying that you can eat dessert every single day, but fasting gives you the ability to occasionally enjoy that dessert because if you feast, you can balance the scale by fasting. It is, after all, the cycle of life. The reason these ‘cheat’ days are important is because it builds compliance. Simply put, it makes the diet easier to follow and changes it into a lifestyle instead. We often counsel that the most important aspect of fasting is to fit it into your life.

Reason #5 – Power

From the Atlantic "Cheap Eats", March 8 2013

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I often treat type 2 diabetic patients. Most of them have had it for 10 years or more. So, of the obese patients I treat, they are often the worst of the worst in terms of obesity and insulin resistance. Sometimes, even a strict LCHF diet is not strong enough. The fastest and most efficient way to lower insulin is intermittent fasting.

In the end, you must ask yourself this question. If you do not eat anything for 1 week, do you think you will lose weight? Even a child understands that you must lose weight. It is almost inevitable. So its efficacy is unquestioned.

There are only two remaining questions. First – is it unhealthy? On the contrary, there are extraordinary health benefits. Two – can you do it? Well, if you never try it, you will never know. I think almost everybody can do it.

Reason #6 – Flexibility

Fasting can be done at any time and in any place. Furthermore, if you do not feel well for any reason, you simply stop. It is entirely reversible within minutes.

Consider bariatric surgery (stomach stapling). These surgeries are done so that people can fast for prolonged periods of time. And they tend to work, at least in the short term. But these surgeries have tons of complications, almost all of which are irreversible.

Furthermore, why would we assume that somebody cannot fast for 1 week or 1 month without ever having tried it?

Reason #7 – Add to any diet

Here is the biggest advantage of all. Fasting can be added to any diet. That is because fasting is not something you do, but something you do not do. It is subtraction rather than addition.

You don’t eat meat? You can still fast.

You don’t eat wheat? You can still fast.

You have a nut allergy? You can still fast.

You don’t have time? You can still fast.

You don’t have money? You can still fast.

You are travelling all the time? You can still fast.

You don’t cook? You can still fast.

You are 80 years old? You can still fast.

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You have problems with chewing or swallowing? You can still fast.

What could possibly be simpler?

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Fasting and Muscle Mass – Fasting Part 15 It seems that there are always concerns about loss of muscle mass during fasting. I never get away from this question. No matter how many times I answer it, somebody always asks, “Doesn’t fasting burn your muscle?”

Let me say straight up, NO.

Here’s the most important thing to remember. If you are concerned about losing weight and reversing T2D, then worry about insulin. Fasting and LCHF will help you. If you are worried about muscle mass, then exercise – especially resistance exercises. OK? Don’t confuse the two issues. We always confuse the two issues because the calorie enthusiast have intertwined them in our minds like hamburgers and french fries.

Weight loss and gain is mostly a function of DIET. You can’t exercise your way out of a dietary problem. Remember the story of Peter Attia? A highly intelligent doctor and elite level distance swimmer, he found himself on the heavy end of the scale, and it was not muscle. He was overweight despite exercising 3-4 hours a day. Why? Because muscle is about exercise, and fat is about diet. You can’t out-run a bad diet.

Muscle gain/ loss is mostly a function of EXERCISE. You can’t eat your way to more muscle. Supplement companies, of course, try to convince you otherwise. Eat creatine (or protein shakes, or eye of newt) and you will build muscle. That’s stupid. There’s one good way to build muscle – exercise. So if you are worried about muscle loss – exercise. It ain’t rocket science. Just don’t confuse the two issues of diet and exercise. Don’t worry about what your diet (or lack of diet –

fasting) is doing to your muscle. Exercise builds muscle. OK? Clear?

So the main question is this – if you fast for long enough, doesn’t your body start to burn muscle in excess of what it was doing previously in order to produce glucose for the body. Hell, no.

Let’s look carefully at this graph by Dr. Kevin Hall from the NIH in the book “Comparative Physiology of Fasting, Starvation, and Food Limitation”. Great

title guys. Amazon probably couldn’t keep enough stock on the shelves.

But anywho, this is a graph of where the energy to power our bodies comes from, from the start of fasting. At time zero, you can see that there is a mix of energy coming from carbs, fat and protein. Within the first day or so of fasting, you can see that the body initially starts by burning

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carbs (sugar) for energy. However, the body has limited ability to store sugar. So, after the first day, fat burning starts.

What happens to protein? Well, the amount of protein consumed goes down. There is certainly a baseline low level of protein turnover, but my point is that we do not start ramping up protein consumption. We don’t start burning muscle, we start conserving muscle.

Reviews of fasting from the mid 1980s had already noted that “Conservation of energy and protein by the body has been demonstrated by reduced … urinary nitrogen excretion and reduced leucine flux (proteolysis). During the first 3 d of fasting, no significant changes in urinary nitrogen excretion and metabolic rate have been demonstrated”. Leucine is an amino acid and some studies had shown increased release during fasting and other had not. In other words, physiologic studies of fasting had already concluded that protein is not ‘burnt’ for glucose.

It further notes that you can get increase leucine flux with no change in urinary nitrogen excretion. This happens when amino acids are reincorporated into proteins. Researchers studied the effect of whole body protein breakdown with 7 days of fasting. Their conclusion was that “decreased whole body protein breakdown contributes significantly to the decreased nitrogen excretion observed with fasting in obese subjects”. There is a normal breakdown of muscle which is balanced by new muscle formation. This breakdown rate slows roughly 25% during fasting.

The classic studies were done by George Cahill. In a 1983 article on “Starvation” he notes that glucose requirements fall drastically during fasting as the body feeds on fatty acids and the brain feeds on ketone bodies significantly reducing the need for gluconeogenesis. Normal protein breakdown is on the order of 75 grams/day which falls to about 15 – 20 grams/day during starvation. So, suppose we go crazy and fast for 7 days and lose about 100 grams of protein. We make up for this protein loss with ease and actually, far, far exceed our needs the next time we eat.

From Cahill’s study, you can see that the urea nitrogen excretion, which corresponds to protein breakdown, goes way, way down during fasting/ starvation. This makes sense, since protein is functional tissue and there is no point to burning useful tissue while fasting when there is plenty of fat around. So, no, you do not ‘burn’ muscle during fasting.

Where does the glucose comes from? Well, fat is stored as triglycerides (TG). This consists of 3 fatty acid chains attached to 1 glycerol molecule. The fatty acids are released from the TG and most of the body can use these fatty acids directly for energy.

The glycerol, goes to the liver, where it undergoes the process of gluconeogenesis and is turned into sugar. So, the parts of the body that can only use sugar have it. This is how the body is able to keep a normal blood sugar even

though you are not eating sugar. It has the ability to produce it from stored fat.

Triglyceride

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Sometimes you will hear a dietician say that the brain ‘needs’ 140 grams of glucose a day to function. Yes, that may be true, but that does NOT mean that you need to EAT 140 grams of glucose a day. Your body will take the glucose it needs from your fat stores. If you decide to EAT the 140 grams instead, your body will simply leave the fat on your ass, hips, and waist. This is because the body will burn the sugar instead of the fat.

But let’s look at some clinical studies in the real world. In 2010, researchers looked at a group of subjects who underwent 70 days of alternate daily fasting (ADF). That is, they ate one day and fasted the next. What happened to their muscle mass?

Their fat free mass started off at 52.0 kg and ended at 51.9 kg. In other words, there was no loss of lean weight (bone, muscle etc.). There was, however, a significant amount of fat lost. So, no, you are not ‘burning muscle’, you are ‘burning fat’. This, of course, is only logical. After all, why would your body store excess energy as fat, if it meant to burn protein as soon as the chips were down? Protein is functional tissue and has many purposes other than energy storage, whereas fat is specialized for energy storage. Would it not make sense that you would use fat for energy instead of protein? Why would we think Mother Nature is some kind of crazy?

That is kind of like storing firewood for heat. But as soon as you need heat, you chop up your sofa and throw it into the fire. That is completely idiotic and that is not the way our bodies are designed to work.

How, exactly does the body retain lean tissue? This is likely related to the presence of growth hormone. In an interesting paper, researchers fasted subjects and then suppressed Growth Hormone with a drug to see what happened to muscle breakdown. In this paper, they already acknowledge that “Whole body protein decreases”. In other words, we have known for 50 years at least, that muscle breakdown decreases substantially during fasting.

By suppressing GH during fasting, there is a 50% increase in muscle break down. This is highly suggestive that growth hormone plays a large role in maintenance of lean weight during fasting. The body already has mechanisms in place during fasting to preserve lean mass and to burn fat for fuel instead of protein.

So let me lay it out as simply as I can. Fat is, at its core essence, stored food for us to ‘eat’ when there is nothing to eat. We have evolved fat stores to be used in times when there is nothing to

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eat. It’s not there for looks, OK? So, when there is nothing to eat (fasting), we ‘eat’ our own fat. This is natural. This is normal. This is the way we were designed.

And its not just us, but all wild animals are designed the same way. We don’t waste away our muscle while keeping all our fat stores. That would be idiotic. During fasting, hormonal changes kick in to give us more energy (increased adrenalin), keep glucose and energy stores high (burning fatty acids and ketone bodies), and keep our lean muscles and bones (growth hormone). This is normal and natural and there is nothing here to be feared.

So, I will say it here, yet again.

1. No, fasting does not mean you burn protein for glucose. Your body will run on fat. 2. Yes, your brain needs a certain amount of glucose to function. But no, you do not have to

EAT the glucose to get it there

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Fasting Lowers Cholesterol – Fasting 16 How can you lower cholesterol without resorting to medications? High cholesterol is considered a treatable risk factor for cardiovascular disease such as heart attacks and strokes. There are many nuances to cholesterol which I do not want to get into, but traditionally, the main division has been between Low Density Lipoprotein (LDL) or ‘bad’ cholesterol, and High Density Lipoprotein (HDL) or ‘good’ cholesterol. Many people do not look so closely at total cholesterol anymore, because there is both good and bad factions and therefore, the total cholesterol gives us little useful information.

We also measure triglycerides, a type of fat found in the blood. Fat is stored in fat cells as triglycerides, but also floats around freely in the body. For example, during fasting, triglycerides get broken down into free fatty acids and glycerol. Those free fatty acids are used for energy by most of the body. So triglycerides are a form of stored energy. Cholesterol is not. This substance is used in cellular repair (in cell walls) and also used for to make certain hormones. One might (mistakenly) think that decreasing dietary cholesterol may reduce blood cholesterol levels. However, 80% of the cholesterol in our blood is generated by the liver, so reducing dietary cholesterol is quite unsuccessful. Studies going back to Ancel Key’s original Seven Country Studies show that how much cholesterol we eat has very little

to do with how much cholesterol is in the blood. Whatever else he got wrong, he got this right – eating cholesterol does not raise blood cholesterol.

The next thought was that lowering dietary fat, especially saturated fats may help lower cholesterol. While untrue, there are still many who believe it. In the 1960’s the Framingham Diet Study was set up to specifically look for a connection between dietary fat and cholesterol. Why haven’t you heard of it, before? Well, the findings of this study showed no correlation between dietary fat and cholesterol whatsoever. Because these results clashed with the prevailing ‘wisdom’ of the time, they were suppressed and never published in a journal. Results were tabulated and put away in a dusty corner.

The Tecumseh study divided their subjects into 3 levels of blood cholesterol – low, medium and high. Then, they looked at how much fat and cholesterol each group ate. It turns out that each group pretty much ate the same amount of fat, animal fats, saturated fats and cholesterol. So,

Framingham Diet Study

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what they demonstrated was that dietary intake of fat does not have very much to do with cholesterol at all.

Low fat and extremely low fat diets can lower the LDL (bad cholesterol) slightly, but they also tend to lower the HDL (good cholesterol) so it is arguable whether things improve or not. Actually, we’ve known that for quite some time. For example, here’s a study in 1995, where 50 subjects were fed either a 22% or a 39% fat diet. Baseline cholesterol was 173 mg/dl. After 50 days of a low fat diet, it plummeted to … 173 mg/dl. Oh. High fat diets don’t lower cholesterol either. After 50 days of high fat diets, cholesterol increased marginally to 177 mg/dl.

Millions of people try a low fat or low cholesterol diet without realizing that these have already been proven to fail. I hear this all the time. Whenever somebody is told their cholesterol is high, they say “I don’t understand. I’ve cut out fatty foods”. Well, reducing dietary fat will not change your cholesterol. So, what to do? Statins, I guess?

“A little starvation can really do more for the average sick man than can the best medicines and the best doctors” – Mark Twain

Studies show that fasting is a simple dietary strategy that can significantly lower cholesterol levels.

Now, there are many controversies about lipids that I do not wish to get quagmired in. I’m only going to discuss the conventional view of it. That is, many of the classic studies, such as the Framingham study, have pointed out that there is a correlation between high levels of ‘bad’ cholesterol and cardiovascular disease. The higher the LDL, the more bad things happen.

HDL

‘Good’ cholesterol (HDL) shows an inverse relationship. High levels are protective. So the lower the HDL, the higher the risk of CV disease. This association is actually much more powerful than that for LDL, so let’s start here. However, it is clear that HDL is not causally related to CV events. They are only a marker for disease.

Several years ago, Pfizer poured billions of dollars into researching a drug called torcetrapib (a CETP inhibitor). This drug had the ability to significantly increase HDL levels. If low HDL caused heart attacks, then this drug could save lives. Pfizer was so sure of itself, it spent billions of dollars trying to prove the drug effective.

The studies were done. And the results were breathtaking. Breathtakingly bad, that is. The drug increased death rate by 25%. Yes, it was killing people left and right like Ted Bundy. Several

more drugs of the same class were tested and had the same killing effect. Just one more illustration of the Correlation is not Causation truth.

What happens to HDL during fasting? You can see from the graph that 70 days of alternate daily fasting had a minimal impact upon HDL levels. There was some decrease in HDL but it was minimal.

Triglycerides

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The story of triglycerides (TG) is similar. While TGs may be correlated weakly to heart disease, they do not cause it. There were several drugs that reduce TG to a much greater extent than the cholesterol medications, the statins. Niacin was one such example. This drug would increase HDL and lower TG without very much effect on the LDL.

The AIM HIGH study tested whether this would have any benefit. The results were stunning. Stunningly bad, that is. While they did not kill people, they did not help them either. And there were lots lot side effects. So, TG, like HDL is only a marker not a causer of disease.

What happens to TG during fasting? There’s a huge 30% decrease in TG levels (good) during alternate daily fasting. In fact, triglycerides is quite sensitive to diet. But it is not reducing dietary fat or cholesterol that helps. Instead, reducing carbohydrates seems to be the main factor that reduces TG levels.

LDL

The LDL story is much more contentious. Certainly, there is a correlation between high LDL levels and CV disease. However, the more important question is whether this is a causal relationship. The statin drugs lower LDL cholesterol quite powerfully, and also reduces CV disease in high risk patients. But these drugs have other effects, often called the pleiotropic (affecting multiple systems) effects. For example, statins also reduce inflammation, as shown by the reduction in hsCRP, an inflammatory marker. So, is it the cholesterol lowering or the pleiotropic effects that are responsible for the benefits?

This is a good question to which I do not have an answer yet. The way to tell would be to lower LDL using another drug and see if there are similar CV benefits. The drug ezetimibe in the IMPROVE-IT trial also had some CV benefits, but they were extremely weak. To be fair, the LDL lowering was also quite modest.

A new class of drugs called the PCSK9 Inhibitors has the power to reduce LDL a lot. The question, though is whether there will be any CV benefit. Early indications are quite positive. But it is far from definitive. So the possibility exists that LDL may play a causal role here. This is, after all, why doctors worry so much about keeping LDL down.

What happens to LDL levels during fasting? Well, they go down. A lot. Over the 70 days of alternate daily fasting, there was about a 25% reduction in LDL (very good). To be sure, drugs can reduce them about 50% or more, but

this simple dietary measure has almost half the power of one of the most powerful classes of

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medications in use today.

In combination with the reduction in body weight, preserved fat-free mass, and decreased waist circumference, it is clear that fasting produces some very powerful improvements in these cardiac risk factors. Don’t forget to add in the reduced LDL, reduced Triglycerides and preserved HDL.

But why does fasting work where regular diets fail? Simply put, during fasting, the body switches from burning sugar to burning fat for energy. Free fatty acids (FFA) are oxidized for energy and FFA synthesis is reduced (body is burning fat and not making it). The decrease in triacylglycerol synthesis results in a decrease in VLDL (Very Low Density Lipoprotein) secretion from the liver which results in lowered LDL.

The way to low ever LDL is to make your body burn it off. The mistake of the low fat diet is this – feeding your body sugar instead of fat does not make the body burn fat – it only makes it burn sugar. The mistake of the Low Carb High Fat diet is this – giving your body lots of fat makes it burn fat, but it will burn what’s coming into the system (dietary fat). It won’t pull the fat out of the body.

Here’s the bottom line for those big-picture, spare-me-the-details kind of folks. Fasting has the following effects:

1. Reduces weight 2. Maintains lean mass 3. Decreases waist size 4. Minimal change in HDL 5. Dramatic reductions in TG 6. Dramatic reductions in LDL

That’s all good. Whether this will all translate into improved cardiac outcomes, I don’t have the answer for you. My guess is Yes.

However, fasting always boils down to this. There’s all these benefits. There’s very little risk. What do you have to lose (other than a few pounds)?

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For people worried about heart attacks and strokes, the question is not “Why are you fasting?”, but “Why are you NOT fasting?”

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Fasting and Hunger – Fasting 17 Does fasting increase your hunger to unimaginable and uncontrollable dimensions? This is often how fasting is portrayed, but is it really true? From a purely practical standpoint, it is not. From my personal experience with hundreds of patients, one of the most consistent, yet surprising things reported is the reduction, not an augmentation of hunger. They often say things like, “I thought I would be consumed by hunger, but now I only eat 1/3 of what I used to, because I am full!” That’s great, because now you are working with your body’s hunger signalling to lose weight instead of constantly fighting it.

The number 1, most common misperception of fasting is it will leave us overwhelmed with hunger and therefore prone to severe overeating. Thus you get pronouncements from ‘experts’ like “Don’t even think about fasting, otherwise you will be so hungry that you will stuff your face full of Krispy Kreme donuts”. Funny enough, these ‘experts’ often have zero experience with fasting either personally or with clients. So why does it seem so reasonable?

Approximately 4-8 hours after we eat a meal, we start to feel hunger pangs and may become slightly cranky. Occasionally they are quite strong. So we imagine that fasting for a full 24 hours creates hunger sensations 5 times stronger – and that will be intolerable. But this is exactly what does NOT happen. Why?

Hunger is, in fact, a highly suggestible state. That is, we may not be hungry one second, but after smelling a steak and hearing the sizzle, we may become quite ravenous. Hunger is also a learned phenomenon, as demonstrated by the classic experiments of Pavlov’s dogs – known in psychology as Pavlovian, or classical conditioning.

In the 1890s, Ivan Pavlov was studying salivation in dogs. Dogs will salivate when they see food and expect to eat (unconditioned stimulus – UCS) – that is, this reaction occurs naturally and without teaching. In his experiments, lab assistants would go in to feed the dogs and the dogs soon began to associate lab coats (conditioned stimulus -CS) with eating. There is nothing intrinsically

appetizing about a man in a lab coat (yummy!), but the consistent association between the lab coat and food paired these two in the dog’s mind.

Very soon, the dogs began to salivate at the sight of the lab coats alone (having now been conditioned) even if food was not available. Ivan Pavlov, genius that he was, noticed this association and started to work with bells instead and before you know it, he was packing his bags to Stockholm to get his Nobel Prize and taste some of those oh-so-delicious Swedish meatballs. By pairing bells and food, the dogs began to anticipate food (salivate) at hearing bells alone without the food. This was the Conditioned Response

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The applicability of this Psychology 101 lesson to hunger is obvious. That is, we can become hungry for many reasons – some of which are natural (smell and sizzle of steak) and others which have become conditioned into us. These conditioned responses can be very powerful and cause great hunger. If we consistently eat breakfast every single morning at 7:00, lunch at 12:00 and dinner at 6:00pm, then the time of day itself becomes a conditioned stimulus for eating. Even if we ate a huge meal at dinner the night before, and would not otherwise be hungry in the morning, we may become ‘hungry’ because it is 7:00. The Conditioned Stimulus (time of 7:00) causes the Conditioned Response (hunger).

Similarly, if we start to pair the act of watching a movie with delicious popcorn and sugary drinks, then the mere thought of a movie may make us hungry even though we have already eaten dinner and would normally not be hungry. The movie is the conditioned stimulus. Food companies, of course, spend billions of dollars trying to increase the number of CS that will make us hungry. The Conditioned Response is hunger – for popcorn, chips, hot dogs, sodas, etc.

Food at the ballgame! Food with movies! Food with TV! Food in between halves of kids soccer! Food while listening to a lecture! Food at the concerts! You can eat with a goat. You can eat on a boat. You can eat in a house. You can eat with a mouse. Conditioned responses, every one.

How to combat this? Well, intermittent fasting offers a unique solution. By randomly skipping meals and varying the intervals that we eat, we can break our current habit of feeding 3 times a day, come hell or high water. We no longer have a conditioned response of hunger every 3-5 hours. We would no longer become hungry simply because the time is 12:00. Instead, we would still get the unconditioned response of hunger, but not the conditioned one. That is, ‘you get hungry because you are hungry’, rather than ‘you get hungry because it’s noon’.

Similarly, by not eating throughout the entire day, we can break any associations between food and anything else – TV, movies, car rides, ball game etc. Here’s the solution. Eat only at the table. No eating at your computer station. No eating in the car. No eating on the couch. No eating in bed. No eating in the lecture hall. No eating at the ball game. No eating on the toilet. (OK, that last one is gross, but I’ve seen it!).

Our current Western food environment, of course, strives to do the opposite. There is a coffee shop or fast food restaurant on every corner. There are vending machines in every nook and cranny of every building in North America. In every conference, even at the Canadian Obesity Network, each break time is greeted by fattening muffins and cookies. Ironic and funny if not so heartbreaking. (Yes, we are doctors that treat obesity. Oh look, muffin! I’ll just eat it in the lecture hall even though I’m not really hungry!)

One key advantage of fasting is the ability to break all these conditioned responses. If you are not accustomed to eating every 4 hours, then you will not start salivating like Pavlov’s dog every 4 hours. If we are conditioned this way, no wonder we find it increasingly difficult to resist all the Mcdonald’s and Tim Horton’s stores while walking around. We are bombarded daily with

Canadian Obesity Network - from www.weightymatters.ca

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images of food, references to food, and food stores themselves. The combination of their convenience and our ingrained Pavlovian response is deadly and fattening.

In breaking habits, you must understand that going cold turkey is not often successful. Instead, it is far better to replace one habit with another, less harmful habit. For example, suppose you have a habit to munch while watching TV – chips or popcorn or nuts. Simply quitting will make you feel that something is ‘missing’. Instead, replace that habit of snacking with a habit of drinking a cup of herbal or green tea. Yes, you will find this weird at first, but you will feel a lot less like something is ‘missing’. So, during fasting, you may, instead of completely skipping lunch, drink a large cup of coffee. Same at breakfast. Or perhaps replace dinner with a bowl of homemade bone broth. It will be easier in the long run. This is, of course, the same reason that people who want to quit smoking often chew gum.

Social influence can also play a large role in eating. When we get together with friends, it is often over a meal, over coffee, or some such dietary event. This is normal, natural and part of human culture worldwide. Trying to fight it is clearly not a winning strategy. Avoiding social situations is not healthy either.

So what to do? Simple. Don’t try to fight it. Fit the fasting into your schedule. If you know you are going to eat a large dinner, then skip breakfast and lunch. One of the easiest ways to fit fasting into your life is to skip breakfast, since that meal is very uncommonly taken with others and, during working days is easy to skip without anybody noticing. This will quite easily allow you to fast for 16 hours (16:8 protocol). Also, unless you go out to lunch every day with the same crowd, lunch is also quite easy to miss without anybody noticing during the work day. This allows you to ‘slip in’ a 24 hour fast without any special effort.

So, in essence, there are two major components to hunger. The unconditioned biological stimuli – that is, the part that will normally stimulate hunger naturally (smells, sights, and tastes of food) and the conditioned stimuli (learned – movie, lecture, ball game). These CS do not naturally stimulate hunger,

but through consistent association, have become almost as powerful. That is, the movie, the TV, the sight of McDonalds, the sound of a jingle etc. They have become hopelessly intertwined but they are by no means irreversibly so. Simply change out the response (drink green tea instead of eat popcorn). Fasting helps to break all the conditioned stimuli, and thus helps to reduce, not enhance hunger. Hunger is not so simple as your stomach being ’empty’.

So – here’s the real question – does fasting lead to over-eating? This was answered in a study published in 2002. 24 healthy subjects underwent a 36 hour fast and then caloric intake was measured. At baseline, subjects ate 2,436 calories per day. After a 36 hour fast, there was an increase in caloric intake to 2914 calories. So there was a degree of over-eating – almost 20%. However, over the 2 day period, there was still a net deficit of 1,958 calories over 2 days. So the amount ‘over’ eaten did not nearly compensate for the period of time fasting. They conclude the “a 36 hr fast..did not induce a powerful, unconditioned stimulus to compensate on the subsequent day.”

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Here’s the ‘spare me the details’ bottom line – NO, fasting does not lead to overeating. No, You will NOT be overwhelmed with hunger.

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Cephalic Phase Response and Hunger – Fasting 18 The relationship between fasting and hunger is, without doubt, the #1 concern we hear. Overcoming hunger seems a daunting task, stemming from a misunderstanding of actual hunger. This is mildly ironic, since my guess is that 95% of us have never, truly been hungry in the sense of starvation, where we did not know when we would be able to eat again. However, I also understand that hunger is one of the most basic human drives/instincts known as the 3 F’s (food, fluids, and procreation).

Much of what we perceive as hunger is actually a learned behaviour, and as such, can be ‘unlearned’. Breaking all the conditioned stimuli of food will help reduce hunger cues. However, there is also a natural need and desire for food. There are unconditioned stimuli – those signals for us to eat – smell, touch, taste, sight of food. The hunger response starts well before food is ingested, and is highly dependent upon hormonal stimuli (gherelin, peptide YY, cholecystokinin, leptin etc). For example, you might think the smell of food increases hunger. But what if you had just stuffed yourself at the All You Can Eat Buffet? The smell of french fries is likely to make you queasy, not hungry.

But, if you are susceptible, then hunger starts in the mind. This is known as the cephalic phase response (CPR). ‘Cephalic’ refers to the brain – so these are measurable physical responses to the suggestion of food and lasts for about 10 minutes. The most obvious of these is the Pavlovian response that we discussed previously. Salivation increases immediately upon the expectation, not the actual delivery of food. Interestingly, the amount of salivation increases when people are shown a picture of a lemon compared to other foods, so clearly the CPR is ‘learned’.

Pancreatic fluid and bicarbonate are also secreted into the stomach well before any food is received. The pancreas also starts to ramp up insulin production and secretion before there is any change in blood glucose levels. Post-prandial thermogenesis – the body heat produced after meals – is also increased. These are measurable responses, although much weaker even in anticipation of food even if no meal is taken afterwards.

The purpose of CPR is to help synchronize the gut response and the incoming food bolus – gut pre-conditioning. If you deliver food directly into the stomach, there is no preparation and subsequent blood sugars are much higher as the body has not had a chance to produce insulin.

Of interest, sweetness itself is not sufficient to start the cephalic response. An unflavored artificial non caloric sweetener by itself did not stimulate insulin secretion. However, when paired with flavour, it may start the the cephalic phase, even if the gastric phase does not proceed (because it has no calories or bulk).

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So, why is this relevant?

First, there is controversy whether you can use non-nutritive sweeteners during fasts (Splenda etc.) Even though there are no calories, this does not negate the cephalic phase response. If the flavour and the sweetener is enough to start the CPR (diet soda, for example), then this will naturally stimulate hunger and the desire to eat. You are chumming the shark infested waters of hunger. If you don’t eat soon, somebody’s gonna get their head bitten off. So, yes, artificially sweetened food can make you hungry.

Diet sodas, in my opinion, are generally not helpful to efforts to fast or lose weight. Recent randomized controlled studies back up the point that diet drinks may sabotage weight loss efforts despite the large decrease

in consumed sugars. Of course, common sense would have told you the same thing. If sweeteners were the answer, we would not have this obesity epidemic, would we? It’s not like people aren’t eating sweeteners. How many people do you know that have tried sweeteners? 95% of everybody? How many people lost significant weight? 2%? There’s your answer right there. The proof is in the pudding. In our IDM program, we prohibit the use of all artificial sweeteners.

However, if the flavouring is weak and CPR is not activated, then use of artificial sweeteners may be OK. There are certainly those that argue that sweeteners help them lose weight by increasing compliance. If so, great. My best advice is to try to fast without the use of sweeteners. If you cannot, then you can try adding a small amount. However, if it makes fasting harder, or prevents you from seeing results, then stop.

The second practical implication of the CPR is that we must remove ourselves food stimuli. Trying to cook a meal while fasting is almost unbearably difficult. To see and smell the food without being able to eat it is hard. This is not simply a matter of weak willpower. Our cephalic phase responses are fully activated. To stop there is like trying to stop a piranha feeding frenzy. Or like trying to stop peeing after you started. (This is actually the way you are supposed to do a urine test). If you can take yourself out away from food stimuli, then keeping to a diet or a fast is infinitely easier. This, of course is the reason you should not shop for food when hungry, or keep cookies/ snacks in the pantry.

That is why one of our most important tips for fasting is to stay busy. I often fast during workdays, because it fits easily into my schedule. I simply work through lunch. By staying busy, I don’t even remember to be hungry. My cephalic phase response has not been activated. If somebody were to put food in front of me, I often cannot resist. But if there is only a pile of paperwork, I just plow right through and forget to be hungry. Then, I get to go home early because I just saved an hour or so.

Hunger comes in waves

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We often imagine that hunger will build and build until it is unbearable and we need to stuff ourselves with Krispy Kreme donuts. however, this is not the case at all. Hunger comes in waves. You just need to ride out the waves.

Remember a time when you skipped lunch. At first, you get hungry. It’s 12:00 noon, but perhaps you are caught up in a meeting and can’t get away. The hunger builds and builds, but there’s nothing to be done. Boss is such a jerk! But what happened at 1:00 or 1:30 or so? The hunger entirely dissipates. The wave has passed. By dinner time, you might remember you missed lunch and eat.

What’s the best way to pass the wave? I find that drinking a cup of green tea or coffee is enough. By the time I’ve finished my cup of green tea, the hunger has passed and I’ve gone onto the next thing to do that day.

Hunger is not predetermined by not eating for a certain period of time. Hunger is a hormonal signal. It does not come about simply because the stomach is ’empty’. Why is this important? Because that explains how people can fast for days without being hungry. This is a consistent finding throughout the scientific literature on fasting as well as in our own IDM program.

For example, Dr. Gilliland, in his description of total fasting found that

A feeling of well-being is certainly engendered in this way and may amount to euphoria. We did not encounter complaints of hunger after the first day. Jeez! People weren’t hungry and actually felt ‘euphoric’ during 14 days of fasting. In fact, some felt so good, they wanted to continue. This was echoed by the experience of Dr. Drenick, of UCLA. Hunger comes quite strongly during the first 1-2 days of fasting. After that, the hunger just subsides and then goes away. Some people speculate that the ketones are actively suppressing appetite.

This explains our response to people who feel they cannot go beyond 24 hours of fasting. We advise them to try 3-7 full days of fasting. Why would we do that? Well, this rapidly gets their bodies used to fasting. By getting over the first 1-2 days, hunger starts to disappear and they become reassured that they are not ‘overwhelmed’ by hunger. Most patients feel that day 2 is the worst. Once they know this and expect it, they are able to handle it.

So, the bottom line?

Hunger is a state of mind, not a state of stomach.

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Circadian Rhythms – Fasting 19 It is sometimes useful to consider things from an evolutionary standpoint. We can look back at early humans and make some general recommendations. Granted, there is little or no proof, but the exercise is still useful and interesting.

There is often great debate about whether we should be eating constantly, or occasionally. Some recommend to eat as soon as you get up and then every 2.5 hours or so during the day. On the other hand, Intermittent Fasting proponents would say that it is quite sufficient to eat once a day or even once every other day. So what’s the truth? First, let me say that there are people who use both systems and do well. But which system makes more sense?

Let’s consider our cousins – the omnivorous wild mammals. It is virtually unheard of, in the natural world, to require feeding 3 times per day, every day in order to stay healthy. Most omnivorous large mammals eat considerably less frequently than that. Obligate herbivores, because of the low caloric density of their food, often require constant grazing – think cows and sheep. Grass, for example has very low caloric density. Much of the grass is indigestible and passes through the cow to exit as manure. Most carnivores, such as lions and wolves will eat only several times per week or even several times per month. Sometimes this is because food is scarce, but even in times of plenty, it’s probably because food is not so easily available. Catching a zebra is much harder than catching a bag of cheetos. This also likely has something to do with caloric density, since most of the animal foods are absorbed by our bodies.

We’ve all seen those TV shows with lions and tigers all around a herd of zebra sleeping away in the hot African sun. Well, those lions were not hungry and therefore did not eat. One meal per week seems to do just fine for them. If a hippo carcass happens to wash up on shore, sure,they’ll eat. So, understand that eating several times per day is not a necessity for omnivores and carnivores. We are not solely driven to eat by nutrient deficiency.

Physical and mental capacity is not impaired by a lion’s week long ‘fast’. If fasting made them sluggish and stupid, well the lion species would not have survived very long. No, the long interval between meals does not impair them in any significant manner. They ate a large meal – storing much of the calories in their bodies and then are using these stored calories to survive. It’s normal.

Mammals have adaptations that allow them to survive with an intermittent food supply. That is, the body has a way of storing food energy, so that lion can eat once a week. This goes for humans as well. The main way to do this is to store glycogen in the liver (stored sugar) and then to store triglycerides in fat tissue. When you eat, you are putting food energy into your stores. When you fast, you are pulling food energy out. It’s inconceivable that mammals are designed with this amazing system for storing food energy and yet it is still necessary to eat every couple

If we were meant to graze, we'd be cows

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of hours to stay healthy. That’s like building an amazing pool and spa, and then arbitrarily deciding that you can’t get wet after all.

Hunter-gatherer societies, as well as wild animals virtually never got the problems of obesity, diabetes of cardiovascular disease, even during times of plenty. It is estimated that animal foods provided about 2/3 of their calories. So, for all the modern teeth gnashing about meat and saturated fats, it seems that our ancestors had little problems eating them. It should also be noted that many societies ate carbohydrate based diets (eg. Kitavans and Okinawans) and also had no problems with obesity. It seems to be a modern problem, and I suspect that refined grains and sugar plays an overwhelming role here.

Things started to change about 10,000 years ago with the agricultural revolution. Early man started to farm instead of hunt, which led to a greater reliability of food allowing a typical pattern of eating 2-3 times per day. Even with that, there was little obesity until relatively recently (1970’s USA).

So, it is certainly possible to eat meat and have little diabesity. It is also possible to eat carbohydrates and have little diabesity. The problem, (Nutritionism’s Greatest Blunder) is focusing obsessively on macronutrient content (how much fat, how much carbs). It’s the insulin response that matters, not the macronutrient breakdown. The toxicity lies in the processing, not the food. So highly refined and processed grains and sugars, as well as vegetable oils are the problem, not carbs and fats.

Circadian Rhythms

Circadian rhythms are predictable, 24 hour self-sustained changes in behaviours, hormones, glandular activity etc. Most hormones of the body, including growth hormone, cortisol and parathyroid hormone are secreted in a circadian rhythm. These rhythms have evolved to respond to differences predominantly in ambient light determined by the season and time of day (which governs food availability). These patterns are seen in virtually all animals from flies to humans, and it is estimated that 10% of a given organism’s genes show circadian changes.

The master circadian clock is the suprachiasmatic nucleus (SCN). It is believed that food was relatively scarce in Paleolithic times are predominantly available during daylight hours. This is mostly because humans hunt and eat by day and once the sun went down, well, you just couldn’t see the food in front of your face. Other animals are nocturnal and may very well have circadian rhythms more suited to eating at night, but not humans.

So, is there a difference between eating during the day and eating at night? Well, the studies are few, but perhaps suggestive. One very interesting study compared the effect of eating a large breakfast versus a large dinner. While there are many association studies, this is one of the few intervention studies done in humans as

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opposed to mice. Most have favoured eating breakfast, or eating earlier in the day, although most studies have too many confounders to be truly useful.

So what this study did was to randomly assign two groups of overweight women to eating a large breakfast (BF group) or a large dinner (D group). Both ate 1400 calories/day, and the macronutrient composition of each diet was matched – only the timing of the largest meal was changed. While both groups lost weight, the BF group was clearly superior for both weight loss and waist size (important measure of visceral fat) by almost 2.5 times (-8.7 kg vs -3.6 kg).

So why there such a huge difference in weight gain? Well, this further graph may explain things a bit. The graph shows the insulin response to meals. The BF group had more insulin in the morning while the D group had more at night, as expected. However, by totalling the Area Under the Curve (AUC – graph to the far right) you can see that overall, the dinner group had a much larger rise in insulin. This is fascinating. The same total calories led to more insulin secretion simply based on meal timing.

An earlier, smaller 1992 study had shown much the same thing. In response to the same meal given either early or late in the day, the insulin response was 25-50% greater in the evening.

Weight gain, of course is driven by insulin. So, while the carbohydrates and calories were identical in both groups, the insulin response was not, translating into more weight for the D group. This illustrates the very important point that obesity is a hormonal, not a caloric imbalance. This study has profound implications over meal timing. There is certainly the well known association of night shift work and obesity. However, this may also have to do with the increased cortisol response due to disturbed sleep.

Now, this does not necessarily mean that you must eat a large meal as soon as you wake up. But it means that perhaps eating a large meal in the evening (after the sun goes down) may cause a much larger rise in insulin than eating that same meal during daylight hours. The problem with breakfast is generally that we are in a hurry in the morning and tend to eat very highly refined carbohydrates (toast, cereal, bagels etc) which tend to also stimulate insulin severely. But waiting until noon to have a large lunch as your main meal seems to be a good solution. This also avoids the ‘rushing out the door’ or ‘grabbing a muffin’ sort of response to the exhortation to ‘eat breakfast – it’s the most important meal of the day’.

Folk wisdom, of course, also advises to avoid eating large meals in the evening. The reason offered usually is something along the lines of “If you eat just before bed, you don’t get a chance

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to burn it off and it will all turn to fat”. Maybe not technically true, but perhaps there is something here. Eating late at night seems to be especially obesogenic.

There is also a natural circadian rhythm to hunger. After all, if it was simply due to food intake, we would consistently be hungry in the morning after the long overnight fast. But personal experience and studies confirm that paradoxically, hunger is lowest in the morning. This is ‘paradoxical’ because the morning time meal follows the longest period of the day without food. Breakfast is typically the smallest, not the largest meal of the day. This indicates that there is a circadian rhythm that is independent of the eat/fast cycle.

Ghrelin, the hunger hormone, shows a marked circadian rhythm with a low at 0800. Interestingly, with fasting, ghrelin peaks at day 1-2 and then steadily falls. This aligns perfectly with what is seen clinically, where hunger is the worst problem on fasting day 1-2. Many people on longer fasts report that hunger typically disappears after day 2.

Hunger typically falls to its lowest level at 7:50 am and peaks at 7:50 pm. This applied to almost all foods. Interestingly, vegetables show no circadian rhythm in desire to eat. I don’t really know what this means but I don’t think it’s because vegetables are not delicious.

Understand once again, that these are natural rhythms that are inherent in our genetic makeup. If you take away all

external stimuli, these rhythms still persist. What does it mean that hunger is lowest in the morning? One implication is that hunger is not so simple as ‘the longer you don’t eat, the more hungry you’ll be’. No, there are many more subtle inputs and hormonal regulation of hunger plays a key role.

However, the studies are conflicting. NHANES data on evening eating failed to show any association between late eating and weight gain, as might have been predicted. Nevertheless, the possibility that eating during daylight hours results in less insulin secretion must be considered.

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So, what’s the practical implication? At 0800 in the morning, our hunger is suppressed actively by our circadian hormonal rhythm. It seems counter-productive to force oneself to eat. What’s the point? Eating does not produce weight loss. Forcing ourselves to eat at a time when we are not hungry is not likely to be a successful strategy.

However, eating late at night also seems to be a poor strategy. Hunger is increased maximally at approximately 7:50 pm at the same time that insulin will be maximally stimulated by foods. This means higher insulin levels for the same amount of food intake. This higher insulin level will naturally drive weight gain. This is the typical pattern of eating in North America, where dinner is the main meal. This is mostly driven, not by health concerns, but by the hours of the working and school day. This also leaves shift workers at a particular disadvantage. They tend to eat larger meals later in the evening, leading to higher insulin.

So the optimal strategy seems to be eating a large meal in the mid-day – sometime between 12:00 and 3:00pm and only a small amount in the evening hours. Interestingly, this is the typical traditional Mediterranean eating pattern. They have traditionally eaten a large lunch, followed by a siesta and then a small, almost snack sized ‘dinner’. While we often think of the Mediterranean diet as healthy due to the foods, the timing of the meals may also play a role.

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Refeeding syndromes – Fasting 20 Complications with refeeding were first described in severely malnourished Americans in Japanese prisoners of war camps in World War 2. It has also been described upon treatment of long standing anorexia nervosa, and alcoholic patients. It is important to have an understanding of these syndromes if you are attempting an extended fast – usually greater than 5-10 days at a time. Re-feeding refers to the period of time immediately after an extended fast when you are just starting to eat again. We’ve touched upon this briefly with ‘how to break a fast’. The two main syndromes are refeeding syndrome and refeeding edema.

In 2003, David Blaine, the magician, emerged from a 44 day water only fast. Opinions abounded regarding whether or not he was cheating, although he was in plain sight the entire time. Doctors recorded every measurement they could think of afterwards during his hospitalization. He lost 24.5 kg (25% of his body weight) and his body mass index (BMI) dropped from 29 to 21.6. Blood sugars and cholesterols were normal. Free fatty acids were high (expected during fasting).

He developed both refeeding syndrome and edema after this stunt. His phosphorus levels fell and required intravenous replenishment.

Re-feeding Syndrome

Refeeding syndrome has been defined as the “potentially fatal shifts in fluids and electrolytes that may occur in malnourished patients”. The key clinical marker of this is hypophosphatemia – very low phosphorus levels in the blood. However, lowered potassium, calcium, and magnesium in the blood may also play a role. Calcium, phosphorus and magnesium are all primarily intra-cellular ions – that is, they are kept inside the cells and blood levels (which are outside of cells) tend to be quite low compared with concentrations inside cells.

Adults store 500-800 grams of phosphorus in the body. Approximately 80% of the phosphorus in our bodies is held within the skeleton and the rest in soft tissues. Almost all of the phosphorus is inside the cell, rather than outside, in the blood. The blood level of phosphorus is very tightly controlled and if it goes too high or low, can cause real problems. Average daily intake of phosphorus is 1g/day, meaning that it often requires many months of undernutrition to produce these syndromes. Protein rich foods, as well as grains and nuts are good sources of phosphorus. 60-70% of the phosphorus is absorbed, mostly in the small intestine.

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Much of the calcium, phosphorus and magnesium in our bodies is stored in the bones. If the body needs more or these intracellular ions, it will take it from the bone ‘stores’. If there is too much, these get deposited into the bone.

During prolonged malnutrition, blood levels of phosphorus remain normal and the deficit is taken from the bones. This can last for a very long time, as was proven with severe malnutrition imposed on the Japanese prisoners of war during World War 2.

But there are some problems that can happen once food is given, particularly carbohydrate containing foods. During the refeeding period, insulin and other hormones are activated. This causes the movement of the major intracellular ions (phosphorus, potassium, calcium and magnesium) into the cells. However, due to overall depletion of body stores, this becomes excessive and too little of these ions are left in the blood. This is what causes the major symptoms of the refeeding syndrome, some of which are rarely fatal.

Phosphorus is used in all cells for energy. The basic unit of energy (ATP) contains 3 phosphorus molecules so severe depletion of phosphorus may cause your entire body to ‘power down’. This typically happens when the serum phosphorus level drops below 0.30 mmol/L. The symptoms include muscle weakness as well as breathing difficulty as the diaphragm (the large muscle powering the lungs) weakens. Outright muscle breakdown (rhabdomyolysis) has been described, as well as heart

dysfunction (cardiomyopathy).

Magnesium is a co-factor in most enzyme systems in the body and severe depletion can result in cramps, confusion, tremor, tetany and occasionally, seizures. Cardiac rhythm abnormalities are also described – classically the pattern known as Torsades de Point. Most magnesium (about 70%) taken orally is not absorbed but excreted unchanged in the feces.

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Potassium may also be shifted into cells, leaving dangerously low levels in the blood. This, too can cause heart rhythm disturbances or even outright cardiac arrest.

Insulin stimulates glycogen, fat and protein synthesis which requires many ions like phosphorus, magnesium, and cofactors like thiamine. The insulin surge puts an enormous demand on phosphorus stores which have been depleted. In essence, the stores of all these intracellular ions has been severely depleted and once the signal is given to replenish, too much phosphorus is taken out of the blood leading to excessively low levels.

So you can see that one of the key pre-requisites for refeeding syndrome is severe, prolonged malnutrition. How common is it? A study of over 10,000 hospitalized patients only found an incidence of 0.43%. These are the sickest of sick people, but still was found rarely. This is actually on overestimate since it also included diabetic ketoacidosis, which is a different mechanism entirely. The main groups that had this disease? Severe malnourishment and alcoholics.

Refeeding syndrome is most often described in the situation of parenteral (intravenous) refeeding in the intensive care unit. These patients are often intubated and cannot eat for weeks. In the setting of relative malnourishment, extremely calorically dense and nutrient rich fluids are introduced directly into the vein. A setup for re-feeding syndrome.

The main risk factor for re-feeding syndrome is prolonged malnutrition. When we use fasting as a therapeutic tool, most people have never missed a single meal in over 25 years! This is hardly the situation that we deal with currently. However, it is important to understand that patients that are severely underweight or malnourished should not fast. This is important because re-feeding syndrome is mostly found in the condition of starvation (uncontrolled, involuntary restriction of food) or wasting (starvation to the point of severe malnutrition) rather than fasting (controlled, voluntary restriction of food).

Vitamin deficiencies have also been described, again mostly with prolonged malnutrition. The most important is thiamine, which is an essential coenzyme in carbohydrate metabolism. Typically, this has been described in alcoholics with the syndromes of Wernicke’s encephalopathy (ataxia, confusion, visual disturbances) and Korsakoff’s syndrome (memory loss and confabulation). Confabulation is a symptom whereby people have a complete lack of short term memory. They therefore ‘make up’ everything when they are talking because they have no memory. There is no intent to deceive. Traditionally, it has been taught to treat alcoholics and other malnourished people with thiamine (intravenous if needed) before treating hypoglycaemia. Theoretically, the glucose may stimulate acute thiamine uptake and precipitating Wernicke’s.

Re-feeding Edema

Insulin acts on the proximal tubule in the kidney to reabsorb sodium and water. Higher insulin levels will result in salt and water retention. Low insulin levels will result in loss of salt and water by the kidney. This has been well described for over 30 years.

During fasting, insulin levels go down quite significantly. This may lead to loss of salt and water. In some extreme cases there is up to 30 pounds of water weight lost, as George Cahill described in his article “Starvation“. The body is not able to hold on to salt and water due to low insulin levels. During re-feeding, especially with carbohydrates, insulin levels start to go back up, and

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the kidney starts to hold onto salt and water extremely tightly. Sodium excretion may fall to less than 1 mEq/day.

In extreme cases, you may actually see gross edema. This can occur as the legs and feet start to become very swollen. Occasionally retention of fluid in the lungs leads to congestive failure in those with heart disease.This has been called”refeeding edema”.

Treatment

Obviously the mainstay of treatment is prevention. Box 3 identifies those at risk of re-feeding syndrome. Obviously the key is to avoid fasting a malnourished person, but that should have been pretty obvious already.

The mainstay of treatment is to start feeds very slowly. Generally this means 50% of the needed food intake with slow increase in rate if no problems are found. This is reflected in the traditional advice to break a fast gently. This is more important the longer the duration of the fasting period. We have often seen people who eat too much as soon as the fasting period is over. Most complain that the food gives them a stomach-ache, but this usually passes quite quickly. I’ve never seen or treated re-feeding syndrome personally, and I hope never to need to.

What happened in the Blaine fast?

There were some differences in the fasting done by Blaine and the ones we use in the IDM program. First, it was a water only fast. Generally, we only use those in severe cases. We allow the use of bone broth during fasts, which is not technically a fast, but provides phosphorus and other proteins and electrolytes. This reduces the chances of developing the refeeding syndrome.

Second, you can see that Blaine is suspended in a Plexiglas box for the duration of his fast. He is not able to do any of his usual activities and does not even stand up for 44 days. This is far more than a fast. His muscles and bones will actually develop significant atrophy during that period. He was losing far more than fat. He lost significant lean weight – muscle and bone, but this was NOT due to fasting. It was due to being cooped up in a box for 44 days.

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During fasting, we encourage our patients to do all their usual activities, especially their exercise program. This helps to maintain their muscles and bones.

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Obesity – Solving the Two-Compartment Problem – Fasting 21 One of the major mistakes made by the Calories In/ Calories Out (CICO) hypothesis is the presumption that energy is stored in the body as a single compartment. They consider that all foods can be reduced to their caloric equivalent and then stored in a single compartment in the body (Calories In). The body then uses this energy for basal metabolism and exercise (Calories Out).

This model looks something like this:

All energy is stored in that one compartment. However, this model is a complete fabrication. It does not exist. This known mis-understanding has led to general acceptance of the CICO theorem. According to this model, by reducing the amount of calories going in, or increasing the amount going out, you may reduce the amount of body energy stored as fat.

Of course, this Eat Less, Move More (or Caloric Reduction as Primary) strategy has a known success rate of about 1% or a failure rate of roughly 99%. This does not deter any of the medical or nutritional authorities to question the sagacity of their advice, though.

To better understand how energy is stored in the body, it is more accurate to use a two compartment model. Dr. Kieron Rooney’s diagram demonstrates that the body is able to derive

energy from 3 sources – glucose (carbs), fat or protein. However, protein is not stored as an energy source and is only used when there is excessive dietary protein after which it is turned to glucose.

So, this leaves two potential fuel sources – glucose and fat – and these are stored in different compartments. Glucose is stored in the liver as glycogen – a molecule that is composed of long chains of sugars. This is easily accessible to the body, but there is a limited amount that is able to be stored. After that threshold is reached, the body stores fat. Think of glycogen like a refrigerator. It is very easy to move food in and out of the fridge, but the storage space is limited.

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Body fat is much more difficult to access, but you may store unlimited amounts. Dietary fat is directly added to the body’s fat stores. Excessive carbohydrates are turned into fat by the process known as De Novo Lipogenesis (DNL). Think of body fat as a freezer that you store in your basement – you can store lots of food in the freezer but it is more difficult to get at it compared to the fridge. You can also store more than 1 freezer in the basement if you need more space.

As you eat, the body stores energy. As you don’t eat (fast), the body must take stored energy from the body to burn for fuel. But it does not take equal amount from both compartments (fat and glycogen). Glycogen is burned almost exclusively until it is finished – this can last 24-48 hours of pure fasting.

This is logical since it is much easier for the body to get at the glycogen. Think about it this way. If you buy groceries, you first store it in the fridge. Once it is

full, then you start to store it in the freezer. When it comes to taking food out to eat, you start by eating the food in the fridge.

Only after almost the glycogen is already burned for energy does the body turns to its stores of fat. Similarly, only

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when the food in the fridge is gone do you want to go downstairs to that cold dank basement to get the food in the freezer. It takes more effort. You do not burn equal amounts of glucose and fat. For example, if your glycogen ‘fridge’ is full, you will not use any of your fat in the ‘freezer’. If you need 200 calories of energy to go for a walk, you take that exclusively out of the glycogen with none of the fat being burned.

The two compartments for energy are not burned simultaneously, but sequentially. You need to empty out the fridge before you can start using the food in the freezer. In essence, the body can either burn sugar or fat, but not both. This is controlled partially by insulin, and also directly by the Randle cycle – described in 1963. This is also sometimes called the glucose-fatty acid cycle.

In isolated heart and skeletal muscle cell preparations, Randle and his colleagues were able to show that cells that were using glucose for energy were inhibited from using fat and vice versa without any interference from insulin or other hormones. This biochemical mechanism directly forbids the body from using both fuels at once. You either burn sugar or fat, but not both. You can see from the diagram that using glucose eventually leads to the production of Malonyl-CoA which inhibits the use of fat (LCFA – Long Chain Fatty Acid).

So, why can’t you lose weight using the CICO method? Because it is based on the incorrect idea that all calories are equal. When you store food energy (calories), it is stored as sugar (glycogen) in the ‘fridge’ and fat in the ‘freezer’. But you must burn through the sugar first before you can start burning fat.

So, now you want to lose body fat. The first thing you need to do is clear out the sugar in your refrigerator. However, if you are continually filling up your fridge 3-6 times a day with sugar, then you will never start burning the fat in the freezer. The CICO method ignores the two compartment problem and pretends that all calories are stored equally and burned equally (single compartment), even though this has been known to be false for at least 50 years. This is the equivalent of the standard calorie restricted diet of eating 3-6 meals a day with a relatively high carbohydrate (50-60%) content.

You imagine that since you are filing up the fridge with less glucose, it will eventually empty. However, this does not happen. Why? Because, as you start putting less food in the fridge, your body senses that and starts to get antsy. So, it starts to make you hungry and want to eat more. If you don’t fill it up, it will decrease your metabolism so that it is burning less energy.

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What’s the solution? First, you could follow a Low Carb, High Fat (LCHF) diet. By severely restricting the amount of carbohydrates, we keep our glucose fridge empty. Now any energy that must be burned must come out of fat freezer. This essentially turns the two compartment problem into a single compartment problem.

Second, you could try intermittent fasting (IF). Fasting essentially burns through all the stored sugars in the fridge quickly. Will you get hungry? Yes, probably. But if you push through that, your body is forced to burn fat for energy. The metabolism does not slow down because of the compensatory hormonal changes of fasting. After several days, hunger is also suppressed – the

mechanism is unknown, but likely related to the ketone production.

The bottom line is this. You can store energy in the form of sugar or fat. In the fasted state – you can either burn sugar or fat for energy, but not both. If you are continually supplying your body with sugar, it will not burn fat.

Fasting provides a very quick way to start burning fat. It provides a solution to the two compartment problem. The reason why the Calorie pundits never understand why their model doesn’t work is because they have fundamentally mis-understood the problem as a single compartment.

Update Jan 28, 2016

I belatedly realized that I forgot to add this section. Actually, it didn’t update, so I thought it was in here but it actually wasn’t. Sorry.

There is one more critical input into the system. How easy is it to get food energy from the freezer? If the freezer is locked away in the basement behind steel gates and barred, then it will be very difficult to get the fat out. What’s the main hormone that controls it? The answer is… insulin. (Actually, insulin is the answer to most of the questions on this blog)

It’s well known that insulin inhibits lipolysis. That’s a fancy way of saying that insulin stops fat burning. Well, that’s normal. Insulin goes up when you eat, so it tells the body to start using the incoming food energy and stop using the fat in the freezer.

So, if your insulin is high from insulin resistance, you may find that your body is not able to get at the fat in the freezer. So, as you lower the incoming calories (Caloric Reduction as Primary strategy – Eat Less) your body is unable to get any fat to burn. So it compensates by reducing caloric expenditure. Hence basal metabolism falls.

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If you are 8 years old, your insulin resistance is minimal and fasting insulin is low. That means it’s really easy to get at the fat in the freezer. It’s like the freezer is right beside the fridge. Easy Peasy. So, if you simply reduce calories, your body can easily compensate by getting some fat out of the freezer.

This explains the time dependence of obesity. That is, those that have been obese for a long time have a much, much harder time losing weight. Because their insulin resistance is high causing elevated insulin levels all the time.

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The Biggest Loser Diet – Fasting 22 The Biggest Loser is a long running American TV reality show that pits obese contestants against one another in a bid to lose the most weight. The show regularly comes under fire from physicians and other health professionals for its over the top portrayal and its fat shaming tactics. A bit of a surprise, then, at how high this diet actually scored in the 2015 USA Today’s rank of best diets to follow. The Biggest Loser Diet scored #3 under the Best Weight Loss category. Shocking. Nevertheless, like a horrific train wreck, it is difficult to avoid watching this show at times and this is why it continues to air new episodes.

First, a bit of background on the actual diet and exercise regimen. Classic Eat Less, Move More. Surely something like this is a good thing, right? What could go wrong? All the ‘experts’ recommend this weight loss regimen. Well, Kai Hibbard, the winner of season three is quoted as saying, “It was the biggest mistake of my life”. Season two’s Suzanne Mendonca says that the reason there’s no reunion show is that “We’re all fat again”. Much of this ‘reality’ series is actually fairly scripted, but this is not the first or last reality series to have that fault.

Luckily, there has been some serious studies done on The Biggest Loser contestants. Dr. Ravussin and Kevin Hall published some fairly extensive metabolic testing on 16 of these contestants. There was a dietary intervention combined with an exercise component. The exercise consisted of 90 minutes per day of vigorous circuit training +/- aerobic training for 6 days a week. This part is often depicted on television, along with some rather questionable fat shaming/ yelling/ screaming by the personal trainers. The exercise portion sometimes far exceeded the allotted time. The fact that vomit buckets were regularly used is an indication that these contestants were pushed quite hard. During their stay on the ranch the minimum time doing physical activity was 2 hours per day.

The dietary component consisted of a calorie restricted diet which was calculated as being about 70% of their baseline energy requirements. Calorie counts often run to 1200 – 1500 per day but it depended upon baseline weight. At baseline, the average weight was 149.2 kg (329 pounds) with a BMI of 49.4. By week 30 (the end of the show’s season), the average weight had dropped to 91.6 kg (202 pounds) – 127 pounds on average! Body fat had dropped from 49% to 28%. Wow. That’s good. Really really good.

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The benefits went beyond that. Measurements of blood glucose, insulin sensitivity had improved. Much of the weight lost was fat, not muscle. This is likely due to the intensive exercise regimen undertaken. While there was some loss of lean mass, it was not much and the majority of the rather impressive weight

loss was, indeed fat.

So, essentially the Biggest Loser diet is Caloric Reduction and Increased Exercise. It’s no wonder the ‘experts’ at US News loves this diet. It is the same Eat Less Move More approach espoused by nutritional authorities everywhere. The Biggest Loser is simply Eat Less Move More on mega doses of steroids. It is the same essential diet, just bigger and badder. Eat Less Move More – looks OK, a little wimpy. Biggest Loser Diet – total badass.

These results are starting to look pretty damn good. So why did all those Biggest Loser contestants gain all their weight back after 6 months? Why do all the Eat Less Move More patients gain all their weight back after 6 months? This is essentially the same question. The simple answer is that metabolic adaptations cause that regain. Specifically, metabolism slows down in response to Caloric Reduction. You start to burn less energy. Your metabolism shuts down.

Let’s see what happened to the Biggest Losers. Virtually all of the contestants slowed down their Resting Metabolic Rates (RMR). The energy they use over 24 hours doing no exercise drops significantly. This is energy that is needed to keep the heart pumping, the lungs breathing, your brain thinking, your kidneys detoxing etc. – your basic metabolism. It drops. Like a piano out of a 20 storey building.

To give you a sense of the magnitude of the drop, from start to week 30, the RMR dropped by 789 calories on average. Now that’s not quite accurate, because as your body weight drops, the RMR is also expected to drop. That is, carrying around all that extra fat still takes some energy. If you correct for this weight loss related drop in RMR, though, there is still an excess

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of 504 calories drop. That is, their metabolism is burning 500 calories less per day than expected correcting for their new, lower weight.

But can’t you make up for this decreased in RMR by increasing exercise? Well, no. Despite a massive increase in the amount of exercise performed by contestants, it was simply not enough to overcome the drastic slowdown in metabolism.

Once you stop having Jillian Michaels screaming in your

ear about how she doesn’t care if you die on the treadmill, the amount of exercise gradually decreases which further exacerbates the weight regain. From week 6 to week 30, physical exertion goes down. But resting energy expenditure (your metabolism) continues its slide downhill. A double whammy.

As you start burning less energy at rest and burn less energy doing exercise, you get the very familiar weight plateau. The weight loss simply stops because your body has shut down to match the lowered caloric intake. Once expenditure drops below intake, you start the even more familiar weight regain. Ba Bam! Weight regain. Goodbye reunion show.

So, here’s the thing. All of this is completely predictable. Since the Caloric Reduction as Primary strategy has a known 99% failure rate, it’s no surprise that the Biggest Loser diet should also have a similarly dismal outlook. So are we doomed to a life of muffin tops? Hardly. There’s another strategy that seems to be far more successful. Intermittent fasting’s bigger, badder surgical cousin – the gastric bypass. These are stomach stapling surgeries that basically force people to fast. The fasting is not quite intermittent, but rather continuous for several months, until the stomach re-expands. The difference is that fasting allows for the numerous hormonal adaptations that keep resting metabolic rates elevated and preserve lean muscle. We’ve talked (incessantly) about the hormonal adaptations to fasting that seem to be highly beneficial. Decreased insulin. Increased growth hormone. Increased adrenalin. These help maintain resting metabolism so that energy expenditure does not decrease.

Hey! We should compare the two strategies directly! Luckily, that study has already been done. Researchers matched 13 gastric bypass patients with 13 Biggest Loser contestants. They lost a

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similar amount of weight, although the Biggest Loser contestants maintained their lean mass much better – likely due to intensive exercise. So they should do better, right?

Not at all.

By six months, the Biggest Loser group had significantly dropped their metabolic rate. While the bypass group did also do so initially, by 12 months the metabolic rate had gone right back up to normal.

Other studies support the metabolic benefit of intermittent severe caloric reduction. Looking at the long term metabolic effect of bariatric surgery, researchers found that 14 months after surgery, the total energy expenditure had dropped by 25%. However, when compared against the expected decrease due to the weight loss, there was no decrease in RMR. As I’ve mentioned before – the difference between daily Caloric Reduction and intermittent fasting is that the hormonal adaptations of calorie reduction is to reduce energy expenditure whereas that of IF is to maintain it.

This makes a huge difference to the long term outcome of patients. If you reduce your

metabolism by 500 calories per day, that means that you are going to be feeling cold, lethargic, and tired because your body has started to shut down. Suppose you start by eating 2000 calories per day. Using Eat Less Move More, you reduce that to 1500 calories per day. Pretty soon, your body is only burning 1500 calories per day. You feel lousy. So, as you increase your calories slightly to 1700, you are still eating less than you used to. But now you are gaining weight. Your body weight goes back up to its original weight as your friends and family silently accuse you of cheating on your diet.

Notice that we are not breaking any ‘Laws of Thermodynamics’. Calories In Calories Out still holds. The point, of course, is that Calories Out is the far more important and decisive factor. However, we focus obsessively on Calories In, which is largely useless. Reducing calories in only reduces calories out.

So, what can we learn from the disaster known as The Biggest Loser? Or the even bigger disaster know as Eat Less, Move More (Caloric Reduction as Primary – aka CRaP)?

1. The Biggest Loser diet is the bigger badass brother of Eat Less, Move More. 2. Eat Less Move More – Proven failure. The Biggest Loser – Proven failure on steroids. 3. Bariatric surgery is the bigger badass brother of Intermittent Fasting 4. Bariatric surgery – proven success, but with surgical complications. Intermittent Fasting

– proven success over thousands of years. No surgical complications.

Pretty clear to me which diet I would choose….

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Fasting and Exercise – Fasting 23 Is it possible to exercise while fasting? This is a common question we hear all the time. People think that food gives them energy and therefore it will be difficult to fast and exercise at the same time. Some people with physically demanding jobs feel that they could not fast and work properly. What’s the truth?

Well, let’s think about this logically for a second. When you eat, insulin goes up telling your body to use some of that food energy immediately. The remainder is stored as sugar (glycogen in the liver). Once the glycogen stores are full, then the liver manufactures fat (DeNovo Lipogenesis). Dietary protein is broken down into component amino acids. Some is used to repair proteins but excess amino acids are turned to glucose. Dietary fat is absorbed directly by the intestines. It doesn’t undergo any further transformation and is stored as fat.

Insulin’s main action is to inhibit lipolysis. This means that it blocks fat burning. The incoming flood of glucose from food is sent to the rest of the body to be used as energy.

So what happens during a fast? Well, it’s just the process in reverse. First, your body burns the stored sugar, then it burns the stored fat. In essence, during feeding you burn food energy. During fasting, you burn energy from your stored food (sugar and fat).

Note that the amount of energy that is used by and available to your body stays the same. The basal metabolic rate stays the same. This is the basic energy used for vital organs, breathing, heart function etc. Eating does not increase

basal metabolism except for the small amount used to digest food itself (the thermic effect of food).

If you exercise while fasting, the body will start by burning sugar. Glycogen is a molecule composed of many sugars all put together. When it comes time to use it for energy, the liver simply starts breaking all the chains to release the individual sugar molecules that can now be used for energy.

As mentioned before, short term storage of food energy (glycogen) is like a refrigerator. The food energy goes in and out easily, but there is limited storage. Long term storage (fat) is like a freezer. Food is harder to get to, but you can store much more of it. If you eat 3 times a day, it’s like you go shopping for food 3 times a day and any leftovers get stored in the fridge. If there is too much for the fridge, it goes into the freezer.

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Julie Moss 1982 Iron Man Triathlon So what happens during fasting and exercise? Well, the body simply pulls energy out of the ‘fridge’. Since you have enough glycogen stored up to last over 24 hours on a regular day, you would need to do some serious exercise for a long time before you could exhaust those stores.

Endurance athletes occasionally do hit this ‘wall‘, where glycogen stores run out. Perhaps there is no more indelible image of hitting the wall as the 1982 Ironman Triathlon where American competitor Julie Moss crawled to the finish line, unable to even stand. Athletes also term complete exhaustion of short term energy stores ‘bonking’. I know some of you may think ‘bonking’ refers to other activities done on all fours, but this is a nutritional blog!

So, how do you get around that? Glycogen stores are not enough to power you through the entire IronMan race. However, you know at the same time, that you are still carrying vast amounts of energy in the form of fat. All that energy is stored away and not accessible during exercise. But the only reason it cannot be used is because your body is not adapted to burn fat.

By following a very low carbohydrate diet, or ketogenic diet, you can train your body to burn fat. Similarly, by exercising in the fasted state, you can train your muscles to burn fat. Now, instead of relying on limited by easily accessible glycogen during competition, you are powered by an almost unlimited energy drawn directly from your fat stores.

Studies are starting to demonstrate the benefits of such training. For example, this study looked at muscle fibres both before and after training in the fasted state. This means that you fast for a certain period of time, usually around 24 hours and then do your endurance or other training. The combination of low insulin and high adrenalin levels created by the fasted state stimulates adipose tissue lipolysis (breakdown of fat) and peripheral fat oxidation (burning of fat for energy). Other studies had already shown that breakdown of intramyocellular lipids (IMCL – fat inside the muscle) is increased by training in the fasted state. Six weeks of training in the fasted state also induced a greater increase of fatty acid binding protein and uncoupling-protein-3 content in muscle.

What does this mean in plain English? It means that our bodies have the wonderful ability to adapt to what’s available. When we fast, we deplete much of the stored sugar (glycogen). Our muscles then become much more efficient at using fat for energy. This happens because muscle ‘learns’ how to use the fat as energy by increasing the amount of proteins that metabolize that fat. In other words, our muscles learn to burn fat, not sugar.

Looking at muscle cells before and after exercise in the fasted state, you can see that there are more muscle bundles, but also that there is a deeper shade of red, indicating more available fat for energy.

Julie Moss 1982 Iron Man Triathlon

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Legendary exercise physiologist and physician Tim Noakes of Cape Town, South Africa has led the way in understanding the benefits of low carbohydrate diets for elite level athletes. Many national level teams (such as the Australian cricket team) are now applying these lessons to crush their competition. Legendary NBA players such as LeBron James, Kobe Bryant and Carmelo Anthony are turning to low carbohydrate, high fat diets to slim down and prolong their careers.

You can be damn certain that these elite level athletes would not be doing this Low Carb mumbo jumbo and training in the fasted state malarky if it had any detrimental effect on their athletic performance. Quite the contrary. Hall of Fame NBA player Steve Nash does not eat simple carbs at any cost. Drinking sugary Gatorade? Not bloody likely to help.

Another study looked at the effects of a 3.5 day fast on all different measures of athletic performance. They measured strength, anaerobic capacity and aerobic endurance. All of these

measures did not decrease during the fasting period.

The body simply switches from burning sugar to burning fat. But, for endurance athletes, the increase in available energy is a significant advantage, since you can store infinitely more energy in the form of fat rather than sugar. If you are running ultra marathons, being able to utilize your almost unlimited fat energy instead of highly limited glycogen energy will mean that you won’t ‘bonk’ and might just win you that race.

During the period where you are adjusting to this change, you will likely notice a decrease in performance. This lasts approximately 2 weeks. As you deplete the body of sugar, your muscles need time to adapt to using fat for energy. Your energy, your muscle strength and overall capacity will go down, but they will recover. So, LCHF diets, ketogenic diets and training in the fasted state may all have benefits in training your muscles to burn fat, but they do require some time to adapt.

Consider an analogy. Imagine that our bodies are fuel tankers. We drive these large tankers around, but only have a limited amount of gas in the gas tank. After the gas tank runs out, we are stuck on the side of the road calling for help. But wait, you might say. That’s ironic. You are carrying an entire tank of gas, but

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ran out of gas. How is that so? Well, that gas is not accessible.

In the same manner, we carry around huge stores of energy as fat. But our muscles are trained to run on sugar, and they run out of energy, so we need to continually refuel despite the large tank of fuel stored as fat.

So, what’s my best advice on physical exertion and fasting? Don’t worry about it. Do everything you normally do during fasting. If you normally exercise, or even if you don’t, you can still do it during fasting. Whether you fast for 24 hours or 24 days, you can still exercise. Your muscles may take up to 2 weeks to become fat adapted, though. During the first 2 weeks of fasting, you may need to take it a little easy, but you should quickly recover after that.

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Fasting and Brain Function – Fasting 24 How does fasting affect brain function? There is very little reliable human data, but some very interesting animal data, as recently reviewed. There are many potential benefits. While I tend to focus on weight loss and type 2 diabetes, there are many other benefits, including autophagy (a cellular cleansing process), lipolysis (fat burning), anti aging effects and anti-seizure effects.

From an evolutionary standpoint, we can look at other mammals for some clues. In many mammals, the body responds to severe caloric deprivation with a reduction in the size of all organs with two prominent exceptions – the brain and the male testicles. This suggests that cognitive function is highly preserved.

This makes quite a lot of sense from an evolutionary standpoint. Suppose you had some trouble finding food. If your brain started to slow down, well, the mental fog would make it that much harder to find food. Our brainpower, one of the main advantages we have in the natural world, would be squandered. No, the brain maintains or even boosts its abilities. In stories of Japanese prisoners of war in World War II (Unbroken by Laura Hillenbrand), many have described the amazing clarity of thought that often accompanies starvation.

The preservation of the size of the testicles is also a significant advantage in trying to pass on our genes to the next generation.

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In all mammals, one of the highly preserved behavioural traits is that mental activity increases when hungry and decreases with satiation. Of course, we have all experienced this. Sometimes this is called ‘food coma’. Think about that large Thanksgiving turkey and pumpkin pie. After that huge meal, are we mentally sharp as a tack? or dull as a concrete block? How about he opposite? Think about a time that you were really hungry. Were you tired and slothful? I doubt it. Your senses were probably hyper-alert and you were mentally sharp as a needle. That is to say that there is likely a large survival advantage to animals that are cognitively sharp, as well as physically agile during times of food scarcity.

Studies have also proven that mental acuity does not decrease with fasting. One study compared cognitive tasks at baseline and after a 24 hour fast. None of the tasks – including sustained attention, attentional focus, simple reaction time or immediate memory were found to be impaired. Another double-blinded study of a 2-day ‘almost total’ caloric deprivation found no detrimental effect even after repeatedly testing cognitive performance, activity, sleep and mood.

What we say we are ‘hungry’ for something (hungry for power, hungry for attention), does it mean we are slothful and dull? No, it means that we are hyper-vigilant and energetic. So, fasting and hunger clearly activate us towards our goal. People always worry that fasting will dull their senses, but in fact, it has the opposite, energizing effect.

These sorts of tests are easy to see in animal studies. Aging rats were started on intermittent fasting regimens are markedly improved their scores of motor coordination and cognitive tests. Learning and memory scores also improved after IF. Interestingly, there was increased brain connectivity and new neuron growth from stem cells. This is believed to be mediated in part by BDNF (Brain Derived Neurotrophic Factor). In animal models, both exercise and fasting significantly increase BDNF expression in several parts of the brain. BDNF signaling also plays a role in appetite, activity, glucose metabolism and autonomic control of the

cardiovascular and gastrointestinal systems.

There are also very interesting mouse models of neuro-degenerative diseases. Mice maintained on IF, compared to normal mice, showed less age related deterioration of neurons and less symptoms in models of Alzheimers disease, Parksinon’s and Huntington’s disease.

In humans, the benefits to the brain can be found both during fasting and during caloric restriction (CR). During exercise and CR, there is increased synaptic and electrical activity in the brain. In a study of 50 normal elderly subjects, memory test improved significantly with a 3 months of CR (30% reduction in calories).

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Neurogenesis is the process where neural stem cells differentiate into neurons that are able to grow and form synapses with other neurons. Both exercise and CR seem to increase neurogenesis via pathways including BDNF.

Even more interestingly, the level of fasting insulin seems to have a direct inverse correlation to memory as well. That is, the lower you are able to drive down fasting insulin, the more improvement on memory score that is seen.

Increased body fat (as measured by BMI) has also been linked to decline in mental abilities. Using detailed measurements of blood flow to the brain, researchers linked a higher BMI to decreased blood flow to those areas of the brain involved in attention, reasoning, and higher function.

Intermittent fasting provides one method of decreasing insulin, while also decreasing caloric intake.

Alzheimer’s disease (AD) is characterized by the abnormal accumulation of proteins. There are 2 main classes – amyloid plaques and neurofibrillary tangles (tau protein). The symptoms of AD correlate closely with the accumulation of these plaques and tangles. It is believed that these abnormal proteins destroy the synaptic connections in the memory and cognition areas of the brain.

Certain proteins (HSP-70) act to prevent damage and misfolding of the tau and amyloid proteins. In mouse models, alternate daily fasting increased the levels of HSP-70. Autophagy removes these tau and amyloid protein when they are damaged beyond repair. This process, too, is stimulated by fasting.

There is substantial evidence that risk of AD is related to obesity. A recent population based twin study demonstrated that weight gain in middle age predisposes to AD.

Taken together, this suggests a fascinating possibility in the prevention of Alzheimer’s disease. Over 5 million American have AD and this number will likely increase rapidly due to the aging

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population. AD creates significant burdens upon families that are forced to care for their afflicted members.

Certainly fasting may have significant benefits in reducing weight, type 2 diabetes along with its complications – eye damage, kidney disease, nerve damage, heart attacks, strokes, cancer. However, the possibility also exists that it may prevent the development of Alzheimer’s disease as well.

The method of protection may also have to do with autophagy – a cellular self cleansing process that may help removed damaged proteins from the body and brain. Since AD may result from the abnormal accumulation of Tau protein or amyloid protein, fasting may provide a unique opportunity to rid the body of these abnormal proteins. We will cover autophagy next week.

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Fasting and Autophagy – Fasting 25 What is autophagy? The word derives from the Greek auto (self) and phagein (to eat). So the word literally means to eat oneself. Essentially, this is the body’s mechanism of getting rid of all the broken down, old cell machinery (organelles, proteins and cell membranes) when there’s no longer enough energy to sustain it. It is a regulated, orderly process to degrade and recycle cellular components.

There is a similar, better known process called apoptosis also known as programmed cell death. Cells, after a certain number of division, are programmed to die. While this may sound kind of macabre at first, realize that this process is essential in maintaining good health. For example, suppose you own a car. You love this car. You have great memories in it. You love to ride it.

But after a few years, it starts to look kind of beat up. After a few more, it’s not looking so great. The car is costing you thousands of dollars every year to maintain. It’s breaking down all the time. Is it better to keep it around when it’s nothing but a hunk of junk? Obviously not. So you get rid of it and buy a snazzy new car.

The same thing happens in the body. Cells become old and junky. It is better that they be programmed to die when their useful life is done. It sounds really cruel, but that’s life. That’s the process of apoptosis, where cells are pre-destined to die after a certain amount of time. It’s like leasing a car. After a certain amount of time, you get rid of the car, whether it’s still working or not. Then you get a new car. You don’t have to worry about it breaking down at the worst possible time.

The same process also happens at a sub-cellular level. You don’t necessarily need to replace the entire car. Sometimes, you just need to replace the battery, throw out the old one and get a new one. This also happens in the cells. Instead of killing off the entire cell (apoptosis), you only

want to replace some cell parts. That is the process of autophagy, where sub-cellular organelles are destroyed and new ones are rebuilt to replace it. Old cell membranes, organelles and other cellular debris can be removed. This is done by sending it to the lysosome which is a specialized organelle containing enzymes to degrade proteins.

Autophagy was first described in 1962 when researchers noted an increase in the number of lysosomes (the part of the cell that destroys stuff) in rat liver cells after infusing glucagon. The Nobel prize winning scientist Christian de Duve coined the term autophagy. Damaged sub cellular parts and unused proteins become

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marked for destruction and then sent to the lysosomes to finish the job.

One of the key regulators of autophagy is the kinase called mammalian target of rapamycin (mTOR). When mTOR is activated, it suppresses autophagy, and when dormant, it promotes it.

Nutrient deprivation is the key activator of autophagy. Remember that glucagon is kind of the opposite hormone to insulin. It’s like the game we played as kids – ‘opposite day’. If insulin goes up, glucagon goes down. If insulin goes down, glucagon goes up. As we eat insulin goes up and glucagon goes down. When we don’t eat (fast) insulin goes down and glucagon goes up. This increase in glucagon stimulates the process of autophagy. In fact, fasting (raises glucagon) provides the greatest known boost to autophagy.

This is in essence a form of cellular cleansing. The body identifies old and substandard cellular equipment and marks it for destruction. It is the accumulation of all this junk that may be responsible for many of the effects of aging.

Fasting is actually far more beneficial than just stimulating autophagy. It does two good things. By stimulating autophagy, we are clearing out all our old, junky proteins and cellular parts. At the same time, fasting also stimulates growth hormone, which tells our body to start producing some new snazzy parts for the body. We are really giving our bodies the complete renovation.

You need to get rid of the old stuff before you can put in new stuff. Think about renovating your kitchen. If you have old, crappy 1970s style lime green cabinets sitting around, you need to junk them before putting in some new ones. So the process of destruction (removal) is just as important as the process of creation. If you simply tried to put in new cabinets without taking out the old ones, it would be pretty fugly. So fasting may actually reverse the entire aging process by getting rid of old cellular junk and replacing it with new parts.

Autophagy is a highly regulated process. If it runs amok, out of control, this would be detrimental, so it must be carefully controlled. In mammalian cells, total depletion of amino acids is a strong signal for autophagy, but the role of individual amino acids is more variable. However, the plasma amino acid levels vary only a little. Amino acid signals and growth factor/ insulin signals are thought to converge on the mTOR pathway – sometimes called the master regulator of nutrient signalling.

So, during autophagy, old junky cell components are broken down into the component amino acids (the building block of proteins). What happens to these amino acids? In the early stages of starvation, amino acid levels start to increase. It is thought that these amino acids derived from autophagy are delivered to the liver for gluconeogenesis. They can also be broken down into glucose through the tricarboxylic acid (TCA) cycle. The third potential fate of amino acids is to be incorporated into new proteins.

The consequences of accumulating old junky proteins all over the place can be seen in two main conditions – Alzheimer’s Disease (AD) and cancer. Alzheimer’s Disease involves the accumulation of abnormal protein – either amyloid beta or Tau protein which gums up the brain system. It would make sense that a process like autophagy that has the ability to clear out old protein could prevent the development of AD.

What turns off autophagy? Eating. Glucose, insulin (or decreased glucagon) and proteins all turn off this self-cleaning process. And it doesn’t take much. Even a small amount of amino acid

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(leucine) could stop autophagy cold. So this process of autophagy is unique to fasting – something not found in simple caloric restriction or dieting.

There is a balance here, of course. You get sick from too much autophagy as well as too little. Which gets us back to the natural cycle of life – feast and fast. Not constant dieting. This allows for cell growth during eating, and cellular cleansing during fasting – balance. Life is all about balance.

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Power: Fasting vs Low Carb – Fasting 26 What’s the difference in power between fasting and LowCarb High Fat (LCHF)? Sometimes it feels like arguing whether Batman or Superman is more powerful (Superman, of course). But they’re both superheros, and the point of both these dietary superhero regimens is to lower insulin. This stems from a rational examination about the causes of obesity and type 2 diabetes. You need to understand the aetiology of obesity (the underlying cause) if you are to have any hope of treating it.

For decades, we have laboured under the false assumption that excessive calories caused obesity. However, overfeeding and underfeeding studies clearly proved this hypothesis wrong. If calories caused obesity, then overfeeding calories should cause obesity. It did, but only in the short term. Long term, weight went back to normal. Underfeeding calories on the other hand, should lead to permanent weight loss. But it did not. The failure rate of this Caloric Reduction as Primary strategy is an abysmal 99%.

Using a more rational model of obesity as a hormonal disorder (mainly insulin, but also cortisol) leads to the hypothesis that increasing insulin should lead to lasting weight gain. Decreasing insulin should lead to weight loss. And guess what? It worked just as advertised. (See the Hormonal Obesity series for a full description).

So, if we understand that excessive insulin causes weight gain, then the treatment is quite clear and just really damned obvious. You don’t need to decrease calories, although there is some overlap. You need to decrease insulin to cause weight loss. Both LCHF diets and fasting accomplish this goal. Refined carbohydrates are the biggest stimulus to insulin, so reducing carbs reduces insulin. Protein, especially animal proteins also raise insulin, so keeping protein moderate and fats high is another way to keep insulin levels down. Fasting, by restricting everything, also keeps insulin down. A ‘fat fast’ ie. eating nothing except pure fat, may also accomplish the same thing, but studies are sparse. So ‘bulletproof coffee’ may certainly achieve the same goal of lowering insulin without lowering calories, but the data are simply no there to say for certain.

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But which diet is better? LCHF or Fasting? A comparison of power shows that fasting wins every time. In this study of a carbohydrate free diet vs fasting in type 2 diabetics, you can see that carb-free does extremely well. If we compare the glucose response of Carb Free versus a Standard Diet, you can see that blood sugars come way down. But fasting does even better.

If you are trying to lower blood glucose, nothing really beats fasting. After all, you can’t

go lower than zero. Even then, the carb-free diet does remarkably well – giving you 71% of the benefits of the fasting, without actual fasting. The standard diet was 55% carbohydrate and 15% protein, and 30% fat – not far off of what most dieticians and Dietary Guidelines recommend. You can see how shitty it is for actual blood glucose control.

The carb-free diet is <3% carbs (that is ketogenic or ultra-low carb), 15% protein (moderate) and 82% fat. LCHF pretty much says it all. The calories delivered were 25 kcal/kg (1750 calories for a 70 kg man) in 3 meals – this was the same between the standard and carb-free diets. So the benefits of carb restriction on blood glucose were NOT simply due to calorie restriction. This is useful knowledge, considering how many ill informed idiots doctors and dieticians keep saying ‘It’s all about the calories’. Actually, in this study, it had nothing at all to do with the calories.

Anybody who still believes that ‘It’s all about the calories’ despite 50 years of unrelenting failure of the Caloric Reduction as Primary (CRaP) model either has not thought about things very hard or is simply not all that intelligent. Yes. If a strategy such as CRaP fails for 50 years, we should be changing our strategy. It doesn’t take Albert Einstein to tell us that is the very definition of insane.

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This graph is pretty sobering. Looking at the Standard Diet (ADA recommended), you can see how high those peaks of glucose really get. You might rightfully ask yourself, if the good folks at the ADA knows that their diet sends blood sugars skyrocketing upwards, why on earth would they recommend it? Are they trying to kill us? Unfortunately, the answer is yes. They are trying to kill you. Not intentionally, but with their ignorance. All that money showered upon them from Big Food and Big Pharma have something to do with it, too.

But what is carb-free just isn’t enough? I have lots of patients who limit their carbohydrates but still have elevated blood sugars. How do you get more power? Sorry, Batman, it’s time to call in Superman. (Don’t bother about the Wonder Twins – they were always useless. One of them would turn into a dolphin or something.) In a word, we need Fasting.

The study results are even more impressive when you look at insulin levels. This is very important because blood glucose levels are not the main driver of obesity and diabetes. Insulin is the main driver. The entire strategy of weight loss hinges upon lowering insulin.

Looking at total area under the curve, you can see that carb free diet can reduce insulin by roughly 50% but you can go another 50% by fasting. That’s power.

This makes sense, of course. A carb free diet will still contain some protein which will increase insulin. The only way to get lower would be to eat 100% fat – which is largely an artificial construct. That is, we don’t generally eat pure olive oil as a meal or pure lard. Bulletproof coffee is certainly a great ‘hack’ but it’s hardly been tested by thousands of years of human history and millions of people. Fasting has survived this test of time. It is Anti-Fragile. How? The more we eat processed and ultra-processed garbage and pretend it is food, the more we need to fast. If you eat a lot of fast food (foods that are ultra-processed and send insulin skyrocketing) the more you need to fast (bring those insulin levels back down).

And NOTHING beats fasting for bringing down insulin. It is simply the fastest and most efficient method of reducing insulin. Luckily, it’s also not as hard as most people believe it to be.

What about glucagon? Remember that glucagon is sort of the opposite of insulin. One of insulin’s main physiologic role is to suppress glucagon. Dr Roger Unger did much to explore the

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biological role of glucagon and often considered it the most important. However, in this study, it had no clinical relevance at all. In dealing with patients, glucagon also plays little or no role.

Let me explain. Insulin causes weight gain – so giving insulin causes weight gain. Does reducing glucagon cause weight gain? Not really. Does increasing glucagon cause weight loss? Not really. Sure, glucagon plays a primary role in rat livers, but I don’t really care. I care about humans.

The bottom line of this study is to reinforce what we knew already. Insulin is the primary (but not the only) driver of obesity. Therefore, for most people, reducing insulin is the best method of treating obesity. Carb free diets are a powerful method of reducing insulin. But if that doesn’t work, then intermittent fasting offers an even more powerful strategy.

In type 2 diabetes, you can reduce blood sugars by 50-70% by carb free diets. You can reduce it another 30% with fasting. So, if we already know how to reduce blood sugars in T2D with dietary strategies – why do we need medications at all? Here’s the answer, of course. You don’t. Type 2 Diabetes is an entirely reversible disease.

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The difference between calorie restriction and fasting – Fasting 27 Perhaps one of the most common questions we get is what the difference is between calorie restriction and fasting. Many calorie enthusiasts say that fasting works, but only because it restricts calories. In essence, they are saying that only the average matters, not the frequency. But, of course, the truth is nothing of its kind. So, let’s deal with this thorny problem.

The weather in Death Valley, California should be perfect with a yearly average temperature is 25 Celsius. Yet, most residents would hardly call the temperature idyllic. Summers are scorching hot, and winters are uncomfortably cold.

You can easily drown crossing a river that, on average, is only 2 feet deep. If most of the river is 1 foot deep and one section is 10 feet deep, then you will not safely cross. Jumping off a 1 foot wall 1000 times is far different than jumping off a 1000-foot

wall once.

In a week’s weather, there is a huge difference between having 7 grey, drizzling days with 1 inch of rain each and having 6 sunny, gorgeous days with 1 day of heavy thundershowers.

It’s obvious in all these examples that overall averages only tell one part of the tale, and often, understanding frequency is paramount. So why would we assume that reducing 300 calories per day over 1 week is the same as reducing 2100 calories over a single day? The difference between the two is the knife-edge between success and failure.

The portion control strategy of constant caloric reduction is the most common dietary approach recommended by nutritional authorities for both weight loss and type 2 diabetes. Advocates suggest that reducing daily caloric consumption by 500 calories will trigger weight loss of approximately one pound of fat per week.

The American Diabetes Association’s main dietary recommendation suggests to “focus on diet, physical activity, and behavioral strategies to achieve a 500–750 kcal/day energy deficit.” The

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‘portion control’ advice to reduce calories has been fairly standard since the 1970s. This reduction is average calories should be spread consistently throughout the day, rather than all at once. Dieticians often counsel patients to eat four, five or six times a day. There are calorie labels on restaurant meals, packaged food, and beverages. There are charts for calorie counting, calorie counting apps, and hundreds of calorie counting books. Even with all this, success is as rare as humility in a grizzly bear.

After all, who hasn’t tried to portion control strategy of weight loss. Does it work? Just about never. Data from the United Kingdom indicate that conventional advice succeeds in 1 in 210 obese men and 1 in 124 obese women (4). That is a failure rate of 99.5%, and that number is even worse for morbid obesity. So, whatever else you may believe, constant caloric reduction does NOT work. This is an empirically proven fact. Worse, it has also been proven in the bitter tears of a million believers.

But why doesn’t it work? For the same reason the contestants of The Biggest Loser could not keep their weight off – metabolic slowdown.

Starvation Mode

The Biggest Loser is a long running American TV reality show that pits obese contestants against one another in a bid to lose the most weight. The weight loss regimen is a calorie-restricted diet calculated to be approximately 70% of their energy requirements, typically 1200-1500 calories per day. This is combined with an intensive exercise regimen typically far in excess of two hours daily.

This is the classic ‘Eat Less, Move More’ approach endorsed by all the nutritional authorities, which is why The Biggest Loser diet scores third on the 2015 USA Today’s ranking of best weight loss diets. And, it does work, in the short term. The average weight loss that season was 127 pounds over 6 months. Does it work long-term? Season two’s contestant Suzanne Mendonca said it best when she stated that there is never a reunion show because “We’re all fat again”.

Their Resting Metabolic Rates (RMR), the energy needed to keep the heart pumping, the lungs breathing, your brain thinking, your kidneys detoxing etc., drops like a piano out of a 20 story building. Over six months, their basal metabolism dropped by an average of 789 calories. Simply stated, they burning 789 calories less per day every day.

As metabolism drops, weight loss plateaus. Caloric reduction has forced the body has shut down in order to match the lowered caloric intake. Once expenditure drops below intake, you start the even more familiar weight regain. Ba Bam! Weight is regained despite dietary compliance with the caloric restriction and even as your friends and family silently accuse you of cheating on your diet. Goodbye reunion show. Even after six years, the metabolic rate does not recover .

All of this is completely predictable. This metabolic slowdown has been scientifically proven for over 50 years. In the 1950s Dr. Ancel Key’s famous Minnesota Starvation Study placed volunteers on a ‘semi-starvation’ diet of 1500 calories per day. This represented a 30% caloric reduction from their previous diet. In response, their basal metabolic rate dropped about 30%. They felt cold, tired, and hungry. When they resumed their typical diet, all their weight came right back.

Caloric restriction diets only work in the short-term, before basal metabolism falls in response. This is sometimes called ‘starvation mode’. Daily calorie restriction fails because it unerringly

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put you into metabolic slowdown. It’s a guarantee. Reversing type 2 diabetes relies upon burning off the body’s excess glucose, so the daily calorie-restricted diet will not work.

The secret to long-term weight loss is to maintain your basal metabolism. What doesn’t put you into starvation mode? Actual starvation! Or at least the controlled version, intermittent fasting.

Fasting triggers numerous hormonal adaptations that do NOT happen with simple caloric reduction. Insulin drops precipitously, helping prevent insulin resistance. Noradrenalin rises, keeping metabolism high. Growth hormone rises, maintaining lean mass.

Over four days of continuous fasting, basal metabolism does not drop. Instead, it increased by 12%. Neither did exercise capacity, as measured by the VO2, decrease, but is instead maintained. In another study, twenty-two days of alternate daily fasting also does not result in any decrease in RMR.

Why does this happen? Imagine we are cavemen. It’s winter and food is scarce. If our bodies go into ‘starvation mode’, then we would become lethargic, with no energy to go out and find food. Each day the situation gets worse and eventually we die. Nice. The human species would have become extinct long ago if our bodies slow down each time we didn’t eat for a few hours.

No, instead, during fasting, the body opens up its ample supply of stored food – body fat! Yeah! Basal metabolism stays high, and instead we change fuel sources from food, to stored food (or body fat). Now we have enough energy to go out and hunt some woolly mammoth.

During fasting, we first burn glycogen stored in the liver. When that is finished, we use body fat. Oh, hey, good news – there’s plenty of fat stored here. Burn, baby burn. Since there is plenty of fuel, there is no reason for basal metabolism to drop. And that’s the difference between long-term weight loss, and a lifetime of despair. That’s the knife edge between success and failure.

Fasting is effective where simple caloric reduction is not. What is the difference? Obesity is a hormonal, not a caloric imbalance. Fasting provides beneficial hormonal changes that happen during fasting are entirely prevented by the constant intake of food. It is the intermittency of the fasting that makes it so much more effective.

Intermittent Fasting vs Calorie Restriction

The beneficial hormonal adaptations that occur during fasting are completely different from simple calorie restriction. The reduction of insulin and insulin resistance in intermittent fasting plays a key role.

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The phenomenon of resistance depends not only upon hyperinsulinemia, but also upon the persistence of those elevated levels. The intermittent nature of fasting helps to prevent the development of insulin resistance. Keeping insulin levels low for extended periods of time prevents the resistance.

Studies have directly compared daily caloric restriction with intermittent fasting, while keeping weekly calorie intake similar. A 30% fat, Mediterranean style diet

with constant daily caloric restriction was compared to the same diet with severe restriction of calories on two days of the week.

Over six months, weight and body fat loss did not differ. But there were important hormonal differences between the two strategies. Insulin levels, the key driver of insulin resistance and obesity in the longer term, was initially reduced on a calorie restriction but soon plateaued. However, during intermittent fasting, insulin levels continued to drop significantly. This leads to improved insulin sensitivity with fasting only, despite similar total caloric intake. Since type 2 diabetes is a disease of hyperinsulinemia and insulin resistance, the intermittent fasting strategy will succeed where caloric restriction will not. It is the intermittency of the diet that makes it effective.

Recently, a second trial directly compared zero-calorie alternate-day fasting and daily caloric restriction in obese adults. The Caloric Reduction as Primary (CRaP) strategy was designed to subtract 400 calories per day from the estimated energy requirements of participants. The ADF group ate normally on eating days, but ate zero calories every other day. The study lasted 24 weeks.

What were the conclusions? First, the most important conclusion was that this was a safe and effective therapy that anybody could reasonably

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follow. In terms of weight lost, fasting did better, but only marginally. This is consistent with most studies, where, in the short term, any decent diet produces weight loss. However, the devil is in the details. The truncal fat loss, which reflects the more dangerous visceral fat,was almost twice as good with fasting as opposed to CRaP. In fat mass %, there is almost 6 times (!) the amount of loss of fat using fasting

The other big concern is that fasting will ‘burn muscle’. Some opponents claim (without any evidence) that you lost 1/4 pound of muscle for every single day of fasting you do. Considering I fast at least 2 days a week, and have done so for years, I estimate my muscle percentage should be just about 0%, and I shouldn’t even have enough muscle to type these words. Funny how that didn’t happen. But anyway, what happened in that study? The CRaP group lost statistically significant amounts of lean mass, but not the IF group. Yes, there is LESS lean muscle loss. Maybe it has to do with all the growth hormone and nor adrenalin being pumped out.

Lean mass % increased by 2.2% with fasting and only 0.5% with CRaP. In other words, fasting is 4 times better at preserving lean mass. So much of that old ‘fasting burns the muscle’.

What happens to basal metabolism? that’s what determines long term success. If you look at the change in Resting Metabolic Rate (RMR). Using CRaP, basal metabolism dropped by 76 calories per day. Using fasting, it only dropped 29 calories per day (which is not statistically significant compared to baseline). In other words, daily caloric reduction causes almost 2 1/2 times as much metabolic slowdown as fasting! So much for that old ‘Fasting puts you into starvation mode’.

Fasting has been used throughout human history as a tremendously effective method of controlling obesity. By contrast, the

portion control strategy of daily caloric restriction has only been recommended for the last 50 years with stunning failure. Yet, conventional advice to reduce a few calories every day persists and fasting is continually belittled as an outdated, dangerous practice akin to blood-letting and voodoo. The study reports that “Importantly, ADF was not associated with an increased risk for weight regain”. Holy S***. That’s the Holy Grail, Man! The whole problem is obesity and The Biggest Loser is WEIGHT REGAIN, not initial weight loss.

Weight regain differed during fasting vs CRaP. The fasting group tended to regain lean mass and continue to lose fat, while CRaP group gained both fat and lean mass. Part of the issue was that the fasting group reported that they often continued to fast even after the study was done. Of course! It is easier than they though, with better results. Only an idiot would stop. One of the very fascinating things is that ghrelin (the hunger hormone) goes up with CRaP but does NOT during fasting. We’ve known forever that dieting makes you hungrier. It’s not a matter of willpower – it’s a hormonal fact of life – the ghrelin goes up and you are hungrier.

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However, fasting does not increase hunger. Fascinating. No wonder it’s easier to keep the weight off! You’re less hungry.

Calorie restriction diets ignore the biological principle of homeostasis – the body’s ability to adapt to changing environments. Your eyes adjust whether you are in a dark room or bright sunlight. Your ears adjust if you are in a loud airport or a quiet house.

The same applies to weight loss. Your body adapts to a constant diet by slowing metabolism. Successful dieting requires an intermittent strategy, not a constant one. Restricting some foods all the time (portion control) differs from restricting all foods some of the time (intermittent fasting). This is the crucial difference between failure and success.

So here’s your choices:

1. Caloric Reduction as Primary: less weight loss (bad), more lean mass loss (bad), less visceral fat loss (bad), harder to keep weight off (bad), hungrier (bad), higher insulin (bad), more insulin resistance (bad), perfect track record over 50 years unblemished by success (bad)

2. Intermittent Fasting: More weight loss, more lean mass gain, more visceral fat loss, less hunger, been used throughout human history, lower insulin, less insulin resistance.

Almost every medical society, doctor, dietician and mainstream media will tell you to use choice #1. I prefer to tell people to take choice #2.

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Why you’re always hungry – Fasting 28 How do you reign in hunger? We all think that eating more will prevent hunger, but is this really true? This is what is behind the advice to eat 6 or 7 times a day. If you can prevent hunger, then you may be able to make better food choices, or eat less. On the surface, it seems pretty reasonable. However, on the surface, the calories in calories out paradigm also seem pretty reasonable, too. Like fool’s gold, appearances can be deceiving, and we must dig deeper to appreciate the truth, otherwise we are the fools. So, let’s think about this a little more.

The advice to eat all the time to prevent hunger assumes that eating a little bit will stave off hunger. Is there any evidence this is true? That would be a big fat no. Somebody made it up, and it’s been repeated so many times that people assume it’s true. Mostly, it’s been promoted heavily by the snack food industry to make sure that people continue to buy their products.

Let’s take some analogous situations. Suppose you need to urinate. Which is easier?

1. Just hold it until you find the right time/place. 2. Pee just a tiny little amount and then stop yourself voluntarily. Do this repeatedly

throughout the day.

You and I know full well that once that first bit of urine come out, there’s no stopping until it’s done. How about this situation? Suppose you are thirsty – which is easier?

1. Keep water out of sight and wait to drink until you find the right time/place and can drink your fill.

2. Drink a thimbleful of water and then voluntarily stop drinking while looking at the full glass of ice cold water. Do this repeatedly throughout the day.

Again, you and I both know that once you get that first sip, there’s no stopping until the glass is empty. in both these cases, it is easier to simply wait. Once you start something, it is easier to continue until satisfied (empty bladder, thirst sated, hunger sated). As with everything in life, there is a certain inertia (the tendency to keep doing what you are doing) to drinking, eating and urinating. It’s like my son. You can’t ever get him into the bath. Once he’s in, you can’t ever get him out of the bath. But this is normal behaviour. So why do we assume this does not apply to eating?

Some people would have you believe that eating a small amount will fill you up so that you can avoid eating so much. If this was true, what is the point of an appetizer? The hors d’oeuvre is literally served ‘outside the main meal’. For what purpose? So that we will spoil our dinner and cannot eat what

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the host has slaved over all day because we are full? Really? No. The whole point of an appetizer is that this is a small tasty morsel to make us eat more.

In French, this may also be called an amuse bouche – meaning literally ‘something that amuses the mouth’. Why? So that we will eat more. It’s not served to fill you up so that you can’t eat that expensive intricate meal prepared by the chef. Virtually all cultures have this tradition to whet the appetite, not dull it. So eating a small, less than satiating amount of food, makes us more hungry, not less. So, eating a tiny bit, enough to make us hungry, and then voluntarily stopping will take enormous willpower throughout the entire day. Not a good idea.

Now think about a time where you weren’t really all that hungry, but it was breakfast time anyways. So you start eating because people have always said it’s the most important meal of the day. To your surprise, as you start eating, you finished an entire meal relatively normally. Before you started eating, you could have easily skipped the meal and have been full. But once you started eating, you ate everything. Has this happened to you? It’s happened to me many, many times, mostly because I’m always aware of this fact.

Eating WHETS the appetite. Got it, McFly? We’ve known this for at least 150 years! Eating all the time so that you’ll eat less sounds really stupid, because it is really stupid. Don’t fall for it. If you hear a doctor or dietician giving you this advice, run far, far away, very very quickly. They will literally kill you with their idiotic advice.

How to stay hungry

So what’s another really great way to increase your hunger and sabotage your weight loss efforts? Calorie reduced diets, of course. The portion control, or Caloric Reduction as Primary (CRaP) strategy of weight loss always leaves you hungry. This is a proven fact.

In a well known study on obesity, researchers took subjects, had them lose 10% of their body weight, and then followed their hormone levels over the next year. Ghrelin (more about this next time) is known as the hunger hormone – higher levels means you are more hungry. Peptide YY is a

satiety hormone – higher levels means your are more full.

After a year of maintaining their weight, there was a substantial difference in patients hormone levels. Ghrelin is much higher (more hungry). Peptide YY is much lower (more hungry). This translated into a measurable difference in hunger between the groups.

The weight loss group is measurable hungrier because their hormones are driving them to be hungrier. This is very important, because there is a tendency to play ‘blame the victim’. When people follow the CRaP advice and then regain their weight because they’re hungry, people think ‘oh, they have no will power’. THAT”S NOT THE CASE AT ALL.

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They are hormonally driven to eat by hunger, so we should stop the silent accusations that people can control it. It’s not their fault. The problem is not with the people, the problem is the advice to eat smaller portions. It is a strategy guaranteed to fail. After all, hunger is one of the strongest basic survival instincts. Yes we can suppress it for a few days. But can we do it day after day, week after week, year after year?

People who have lost weight are physically, measurable hungrier than those that have not. You cannot solve this problem of long term weight loss until you understand how to curb hunger. What is the answer?

Well, in case you haven’t figured it out yet, this only being the 28th post on fasting and all, the answer is fasting. There’s a certain logic here. If you eat all the time, you will get more hungry. If you eat less, you will get less hungry. How does that work? We’ll see next week….

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Fasting and Ghrelin – Fasting 29 Ghrelin is the so-called hunger hormone. It was purified from rat stomach in 1999 and subsequently cloned. It binds to growth hormone (GH) secretagogue receptor, which strongly stimulates GH. So, for all you people who thought that eating makes you gain lean tissue, it is actually the opposite. Nothing turns off GH like food. Of course, food provides the nutrients needed to grow, so in fact, you need both feeding and fasting cycles to properly grow. Not all feeding, and not all fasting. Life lies in the balance of the two. The cycle of life is feast and fast.

Ghrelin, has also been found to increase appetite and weight gain. It also antagonizes the effect of leptin (in rats at least). Leptin, as you might recall, is the hormone produced by fat cells which turns off appetite and makes us stop eating. Ghrelin turns on appetite. So, if you want to lose weight on a long term basis, you need to tune down ghrelin.

So, how to do that? As we discussed last week, eating all the time sounds like it will turn off hunger and ghrelin. But that’s far too simplistic. Surprisingly, the answer is the opposite – fasting.

Let’s look at this study “Spontaneous 24-h ghrelin secretion pattern in fasting subjects“. Patients undertook a 33 hour fast, and ghrelin was measured every 20 minutes. Here’s what ghrelin levels look like over time.

There are several things to notice. First, ghrelin levels are lowest at approximately 9:00 in the morning. This corresponds to

the measures of the circadian rhythm which find consistently that hunger is lowest first thing in the morning. Recall that this is also generally the longest period of the day where you have not eaten. This reinforces the fact that hunger is not simply a function of ‘not having eaten in a while’. At 9:00, you have not eaten for about 14 hours, yet you are the least hungry. Eating, remember, does not necessarily make you less hungry.

Next, notice that there are 3 distinct peaks corresponding to lunch, dinner and the next day’s breakfast. BUT IT DOES NOT CONTINUALLY INCREASE. After the initial wave of hunger, it recedes, even if you don’t eat. Ghrelin shows a “spontaneous decrease after approximately 2 h without food consumption”. This correlates perfectly to our clinical experience that ‘hunger comes in waves’. If you simply ignore it, it will disappear. Think of a time that you were too busy and worked right through lunch. At about 1:00 you were hungry, but if you just drank some tea, by 3:00 pm, you were no longer hungry. Ride the waves – it passes. Same goes for dinner. Further it has been shown that ghrelin spontaneously decreases independently of serum insulin or glucose levels.

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Also, note that ghrelin does have a learned component since all these subjects were used to eating 3 meals per day. It is not merely by coincidence that these peaks of ghrelin happen. This is similar to the ‘cephalic phase’ of insulin secretion that we’ve discussed previously.

There was one other big finding of this study. Look at the average ghrelin levels over 24 hours. Over the day of fasting, ghrelin stays stable! In other words, eating nothing over 33 hours made you no more or less hungry than when you started! Whether you ate or did not eat, your hunger level stayed the same.

As we discussed in our last post – eating more sometime makes you more hungry, not less. In the same vein, eating less can actually make you physically less hungry. That’s terrific, because if you are less hungry, you will eat less, and are more likely to lose weight.

So what happens over multiple days of fasting? This study looked at the question specifically. 33 subjects had their ghrelin measured over 84 hours of fasting and they divided the results by men and women, as well as obese and lean. There were no significant differences between the lean and obese subjects, so I won’t dwell on that further. Once again, there were distinct circadian variations.

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Over 3 days of fasting, ghrelin gradually DECREASED. This means that patients were far LESS hungry despite not having eaten for the past 3 days. This jives perfectly with our clinical experience with patients undergoing extended fasting. They all expect to be ravenously hungry, but actually find that their hunger completely disappears. They always come in saying ‘I can’t eat much anymore. I get full so fast. I think my stomach shrank’. That’s PERFECT, because if you are eating less but getting more full, you are going to be more likely to keep the weight off.

Notice, also the difference between men and women. There’s only a mild effect for men. But the women show a huge decrease in ghrelin. Again, this addresses one of the major worries that women are not able to fast. Actually, women would be expected to have more benefit from fasting because their hunger can be expected to decrease better than men. Notice, too, how much higher women’s ghrelin level reaches. I suspect this correlates to the clinical observation that many more women are ‘addicted’ to certain foods eg. chocoholics. Sugar addicts. etc. So many women have remarked how a longer fast seemed to completely turn off those cravings. This is the physiologic reason why.

A few other notes about the hormonal changes of fasting. Notice that cortisol does go up during fasting. Yes, fasting is a stress to the body and cortisol acts as general activator as well as trying to move glucose out of storage and into the blood. So, if too much cortisol is your problem, then fasting may not be right for you.

Insulin also goes down, which is what we expect. Growth hormone, as we’ve previously noted, goes up during fasting. I suspect this helps to maintain lean muscle tissue and to rebuild lost protein when you start to eat again.

However, the main point of this post is to show that over intermittent and extended fasting, ghrelin, the main hormonal mediator of hunger does not increase to unmanageable levels. Rather it decreases – which is exactly what we are looking for. We want to eat less, but be more full. Fasting, unlike caloric restriction diets is the way to do that.