Atkins’ Diet:Atkins’ Diet: Does it REALLY Work? Does it REALLY Work?

Dr. Christine Simpson, MD Dr. Christine Simpson, MD FRCPCFRCPC

General Internal MedicineGeneral Internal Medicine

CHIP Director, EdmontonCHIP Director, Edmonton

Who? Who?

• Dr. Atkins, cardiologistDr. Atkins, cardiologist

• Sold 10 million copies of his book, Sold 10 million copies of his book,

“ “Diet Revolution”, copyrighted Diet Revolution”, copyrighted 1973 1973

• Other contemporaries:Other contemporaries:– ““The Zone”, by SearsThe Zone”, by Sears– ““Protein Power”, by EadesProtein Power”, by Eades

Why?Why?

• Obesity epidemic began in the late 70’sObesity epidemic began in the late 70’s

• Continual spiral upwards, despite the Continual spiral upwards, despite the

low-fat dietary messages promotedlow-fat dietary messages promoted

by the medical professionby the medical profession

• 60% Americans overweight (BMI >25),60% Americans overweight (BMI >25),

30% are obese (BMI >30)30% are obese (BMI >30)

What?What?

• During the 1970’s, new concepts about fatDuring the 1970’s, new concepts about fat

* primary nutritional evil* primary nutritional evil

* especially saturated fat of meat & dairy* especially saturated fat of meat & dairy

• Atkins countered this by promising weightAtkins countered this by promising weight

loss while eating steak, eggs and butter toloss while eating steak, eggs and butter to

our heart’s content BECAUSE:our heart’s content BECAUSE:

* carbs cause obesity and heart * carbs cause obesity and heart diseasedisease

Atkins’ motto:Atkins’ motto:

•FAT IS FAT IS HARMLESS!!!HARMLESS!!!

One follower says of the One follower says of the diet:diet:• Atkins allowed his readers to eat “truly Atkins allowed his readers to eat “truly

luxurious foods without limit,” as he put it, luxurious foods without limit,” as he put it, “lobster with butter sauce, steak with “lobster with butter sauce, steak with bearnaise sauce…bacon cheeseburgers,” bearnaise sauce…bacon cheeseburgers,” but allowed no starches or refined but allowed no starches or refined carbohydrates, which means no sugars or carbohydrates, which means no sugars or anything made from flour. Atkins banned anything made from flour. Atkins banned even fruit juices, and permitted only a even fruit juices, and permitted only a modicum of vegetables, although the latter modicum of vegetables, although the latter were negotiable, as diet progressed. were negotiable, as diet progressed.

Garry TaubesGarry Taubes

How? How?

• High glycemic index foods (carbs that areHigh glycemic index foods (carbs that are

absorbed quickly) promote absorbed quickly) promote hyperglycemiahyperglycemia

…….an insulin surge…..then hypoglycemia.an insulin surge…..then hypoglycemia

• This leads to hunger and MORE carbsThis leads to hunger and MORE carbs

carvings; hence, increased caloric intakecarvings; hence, increased caloric intake

• During the insulin surge, sugar is During the insulin surge, sugar is

transformed into FAT and muscletransformed into FAT and muscle

The hypothesis:The hypothesis:

• With a carb-depleted diet, there are NOWith a carb-depleted diet, there are NO

insulin surgesinsulin surges

• When cellular glucose is depleted, fat When cellular glucose is depleted, fat and muscle metabolism (break-down) and muscle metabolism (break-down) beginsbegins

• This is the process called “ketosis”, This is the process called “ketosis”, which is identical to that seen in which is identical to that seen in starvationstarvation

Is there any scientific Is there any scientific evidence?evidence?• Up until 2002, virtually nothingUp until 2002, virtually nothing

• Most “evidence” was anecdotalMost “evidence” was anecdotal

• The best scientific evidence requires:The best scientific evidence requires:

* a randomized, controlled trial * a randomized, controlled trial

testing two groups of subjects:testing two groups of subjects:

a) Atkins diet versusa) Atkins diet versus

b) high carb dietb) high carb diet

* Must look for benefits AND harm over time!* Must look for benefits AND harm over time!

Two recent scientific Two recent scientific studies:studies:

• July 2002, July 2002, American Journal of American Journal of MedicineMedicine

• May 2003, May 2003, New England Journal New England Journal

of Medicineof Medicine

• Funded by the National Institute of Funded by the National Institute of HealthHealth

The Details:The Details:

• 132 people, average weight 286 pounds132 people, average weight 286 pounds

• 63 people, average weight 217 pounds63 people, average weight 217 pounds

• Low carb (25-30 g/day, ~100-120 Cal)Low carb (25-30 g/day, ~100-120 Cal)

• High carb (200-300 g/day, ~1200 Cal,High carb (200-300 g/day, ~1200 Cal,

25% fat)25% fat)

Followed for ONLY one year!Followed for ONLY one year!

The Results:The Results:

• Low carb:Low carb:– 1) in 6 months, lost1) in 6 months, lost

13 pounds13 pounds

- 2) in 6 months, lost- 2) in 6 months, lost

15 15 pounds;pounds;

regained 1/3regained 1/3

- HDL increased by 18%- HDL increased by 18%

-Trigs decreased by 28%-Trigs decreased by 28%- No diff in LDL or BPNo diff in LDL or BP

• High carbHigh carb– 1) in 6 months, lost1) in 6 months, lost

4 pounds4 pounds

- 2) in 6 months, lost- 2) in 6 months, lost

7 pounds;7 pounds;

regained regained 1/51/5

- HDL increased by 3%- HDL increased by 3%- Trigs increased by 1%Trigs increased by 1%- No diff in LDL or BPNo diff in LDL or BP

The Conclusion:The Conclusion:

• A carb-depleted diet results in greater A carb-depleted diet results in greater

weight loss in 6 months, and does not weight loss in 6 months, and does not cause significant harm to the lipid cause significant harm to the lipid profile (perhaps even a benefit?).profile (perhaps even a benefit?).

• ie. “A healthy, short-term method forie. “A healthy, short-term method for

weight loss!”weight loss!”

??????????????????????????????????????????????????????????????????

•Does that really Does that really make sense?make sense?

Studies are inherently Studies are inherently flawed!flawed!

• Flawed in design and interpretationFlawed in design and interpretation

• Very low sample size, very short-Very low sample size, very short-termterm

• 40% drop-out rate (same in both 40% drop-out rate (same in both groups)groups)

What we were NOT told:What we were NOT told:

• Carb-eaters caught up with weight Carb-eaters caught up with weight loss during the 2loss during the 2ndnd 6 months 6 months

• Diet compositions were actually NOTDiet compositions were actually NOTdrastically different:drastically different:

* 41% (Atkins) fat versus 33%* 41% (Atkins) fat versus 33%* Dean Ornish says:* Dean Ornish says:

“ “they have compared two diets, they have compared two diets, neither of which is very effective” neither of which is very effective”

An even closer look:An even closer look:

• Most of the weight lost in the Atkins dietMost of the weight lost in the Atkins diet

group was due to a decreased total group was due to a decreased total

amount of consumed calories!amount of consumed calories!

• The initial weight loss is water, followed The initial weight loss is water, followed

by fat AND muscle; is ketosis dangerous?by fat AND muscle; is ketosis dangerous?

• The lipid profile changes can not be The lipid profile changes can not be

considered secondary to diet considered secondary to diet compositionscompositions

One more point:One more point:

• Ketosis theory and blood sugar/insulinKetosis theory and blood sugar/insulin

surge mechanism:surge mechanism:

- NOT true when whole grains, legumes,- NOT true when whole grains, legumes,

and high-fiber fruits and vegetablesand high-fiber fruits and vegetables

are consumedare consumed

““Foods as grown, simply prepared!”Foods as grown, simply prepared!”

The REAL scientific The REAL scientific conclusion:conclusion:• ““longer and larger studies are requiredlonger and larger studies are required

to determine the long-term safety and to determine the long-term safety and efficacy of low-carbohydrate, high-protein, efficacy of low-carbohydrate, high-protein, high-fat diets.”high-fat diets.”

• The debate continues, but the studies to date The debate continues, but the studies to date do NOT prove superiority of an Atkins-style do NOT prove superiority of an Atkins-style diet over a high COMPLEX carbohydrate diet;diet over a high COMPLEX carbohydrate diet;

• Rather, they simply re-emphasize that Rather, they simply re-emphasize that calorie restriction aids in short-term weight calorie restriction aids in short-term weight loss.loss.

Any volunteers for further Any volunteers for further studies?studies?

•Questions?Questions?

•Comments?Comments?

Point 1:Point 1:

•Save a quarter on Save a quarter on your food bill…your food bill…

… …and add 10 years to and add 10 years to your life!your life!

Point 2:Point 2:

•Don’t tell them it’s Don’t tell them it’s healthy… healthy…

… …tell them it’s tell them it’s cheap!cheap!