Chapter 7 - Body Composition Basics

Coming Up..

• Understand basic composition

• factors that influence your body composition

• relationship between body composition and health

• Body Comp Measurements

6packs are Just a Shortcut Away Right?

Guess the Weight in each photo

Basics of Body Composition• Body composition• The relative proportions of different types of body

tissues (all tissues)• Fat • Fat-free mass• muscle, bone, organs, fluids

• Percent body fat is the measure most often used to define and evaluate body composition

Basics of Body Composition (continued)

• Storage fat• Visceral fat• Found deep within the abdominal cavity• Surrounds internal organs

• Subcutaneous fat• Found just beneath the skin• Insulates the body and regulates temperature

Basics of Body Composition (continued)• Essential fat • 8-12 % in females and 3-5 % in males

• Necessary for normal body function

• Found in the central nervous system, bone marrow, and other organs• Surrounds nerve fibers in the brain allowing for the

transmission of messages

• Key component of cell membranes

• Important in healthy hormone production

What Do you think each Body Fat is in this Picture?

Well..

Compare

Fig 7-1 Body composition of young adults (ages 20-24)

Fig 7-2 Visceral and subcutaneous fat in the abdomen

.

Basics of Body Composition (continued)• Metabolism• A processes that requires energy (calories from foods)

and maintains body functioning.• Energy balance

Metabolism is…• The amount of energy your body requires depends

on three criteria: 1. Resting Metabolic Rate (RMR)• (AKA basil metabolic rate)

2. Dietary thermogenesis3. Physical activity

Basics of Body Composition (continued)• RMR• Energy required to maintain essential body

processes at rest

• Depends on genetics, body size, and body composition

• Muscle is more metabolically active than fat

• Resistance training increases RMR

Basics of Body Composition (continued)• Dietary thermogenesis• The energy required to digest and process food

• Protein burns more calories than carbs to diegest because it takes more calories to break it down and convert it to glucose!

Example• FRED and BILL both weigh 200lbs and have a BMR

of 3,500 kcal a day. They both want to lose weight. • Fred eats 2,500 kcal or protein, 450 fat, and 50carbs• Bills eats 1,500kcal protein, 400 carbs, and 100 fat

• Who do you think will drop more lbs.

Basics of Body Composition (continued)• Physical activity• Energy expended in daily living as well as formal

exercise

Carmen Question: Spot Reduction• Question: “In the book it said, “it is impossible to

target one area for fat burning. You can strengthen the muscles in a particular area of your body through exercise, but such workouts will not reduce fat from specific area” but if you are building muscle in an area aren’t you reducing fat in that area to make room for the new muscle? “

• Answer: Muscle and fat are different types of tissue, they can both grow and they can both reduce simultaneously . One can also grow while the other can reduce…• Examples…

Basics of Body Composition (continued)• How do we get fat?

• 3,500 calories is the equivalent of a pound of body weight

• Most fat is stored in fat deposits, which are about 80 percent fat and 20 percent support cells, immune cells, and blood vessels.

• If you gain weight as fat, these fat cells enlarge, storing more fat. If you lose body fat, your fat cells shrink

Basics of Body Composition (continued)• Overweight• Overweight is excessive weight for height and does

not consider body composition• Based on large-scale population studies• Potential issues?

Basics of Body Composition (continued)• Obesity• Higher degree of overweight, characterized by

excessive body fat; obesity may also be defined by body weight or a related measure

• The prevalence of obesity among Americans has increased significantly, particularly in the 1980s

• 70 percent of Americans are overweight or obese..

Fig 7-4 Average percent of body fat by age and gender

Factors AffectingBody Composition (continued)

• Gender• Age• Genetics• Lifestyle • Sleep• Diet

• GENDER AND AGE???• Apple/pear paradox• Hormones

Figure 7-5 Body-fat distribution

Carmen Question“Why does eating too little and burning excess calories through exercise not cause your body fat percentage to decrease, but instead decreases your lean muscle mass? I thought that when the body was in distress due to not enough calorie consumption the excess fat was the first type of tissue that gets consumed. “

Carmen Question• “While reading over the chapter, calories and

weight were talked about frequently. Well, I know when anyone tries to lose weight they stay away from eating bad calories like candy and chips, even though they crave it. My question is….are “cheat” days really okay to do? I know it won’t affect your weight too much if you are consistently working out and lifting, but say you just ate awful for a whole day…what affect would that have on your body, or does it depend on the person?”

AnswerMuscle tissue burns 7 to 10 calories per pound per day.

Fat burns 2-3 calories per day per lb

if you replace a pound of fat with a pound of muscle, you can expect to burn only approximately 6-4 more calories a day That's 450-900 more calories burned per month, or 5,400-10,800 more calories burned in a year—that's about a 3-pounds per lb of muscle replacing fat!

Obesity Paradox

• Component of health-related fitness• Some fat is healthy • Maintaining an appropriate level of body fat is vital to

a healthy, longer life

Body Composition and Wellness (continued)

• Problems associated with excess body fat

• Cardiovascular disease• High blood pressure and fat in the blood

• Type 2 diabetes• There is a direct relationship between excess

body fat and type 2 diabetes

• Cancer• Increase risk of cancer of the breast, prostate,

colon, pancreas, esophagus, endometrium, and kidney

Assessing Body Composition• It is hard to define ideal weight• Consider body composition

• Ideal weight• Percent fat better than scale weight

• BMI• Weight (kg)/Height2 (m)

•BMI does not take into account muscle mass•An Indirect Measure of Body Fat

Carmen Question • “Genetic factors significantly contribute to body

composition, how much does environmental factors contribute to body composition and what is rate that children deviate from how their parents behave in regards to fitness?”

Body Composition and Wellness (continued)• Factors that can make a difference• Body fat distribution

• Visceral or abdominal fat increases the risk of chronic disease

• Other health risk factors• Additional risk factors

• Lifestyle• Obese people spend a greater portion of their life with

disabilities

Carmen Questions• Body Composition Question:• I am a pretty fit individual. While I would say I am

slightly overweight, I am still very active in strength training, cardio, five intramural sports/ semester, etc. My BMI still comes out to be 28.4ish. This means I am on the threshold of being high risk- obese. When do tests like these provide incorrect results? Is there a better test I should use?

Carmen Question: Body Comp Testing• Who can do this:• ANYONE!!! There is no right time to do this.

• You can even get it done for free at the bottom floor of the PAES building in the exercise science department!

• Is it accurate? Let’s see…

What do you think is the most appropriate measurement for your group’s goal?

Measure Body Fat Percentage #5: DEXA Scan• Upside• Very accurate• Downside• Expensive:

Around $250 • Not repeatable

(unless you don’t mind spending $250 every couple weeks)

Measure Body Fat Percentage #4: Hydrostatic Weighing• Upside• Very accurate,

considered Gold Standard• Downside• Impractical • Expensive • Not repeatable

(unless you liked repeatedly getting dunked in a tank and spending $150)

Measure Body Fat Percentage #3: Anthropometric• Upside• Easy to

Administer • Cheap• Downside• Questionable

Accuracy (Body fat is not directly measured)

Measure Body Fat Percentage #2: Bioelectric Impedance Analysis• Upside• Very easy to

administer • Inexpensive (most

weight scales around $50 or even less have BIA)• Downside• Questionable

Accuracy • Variability of results

dependent on hydration level

Measure Body Fat Percentage #1: Skin Fold Caliper• Upside • Accurate • Dependable (when skilled

at measuring) • Repeatable

• Downside• Variability of measurement

(same exact spot needs to used each time)

• More than one-site test requires a skilled fitness professional (I’ve done these thousands of times!)

• For people 35+ pounds overweight, fat may not fit within caliper, so it’s less accurate

Carmen Question: activity and body fat• Question • “Is high-intensity exercise better than low-intensity

exercise for fat loss?”

• “Is aerobic exercise better than resistance exercise for fat loss?”

•  • “How does body fat affect gaining muscle? Does

having more body fat increase the ability to gain muscle?”

• Answer: get out your note pads!

Table 7-2 Body mass index (bmi) classification and disease risk

Table 7-4 Approximate calorie costs of selected physical activities

Female Triad

• Problems associated with too little body fat• Female athlete triad

• Energy availability• Menstruation• Amenorrhea

• Bone health

Figure 7-6 The female athlete triad

Body Composition and Wellness (continued)

• Body composition and athletic performance• Many factors beyond body composition determine

performance

• All being equal, a decreased level of body fat (that is still in the healthy range) might improve your performance and reduce your susceptibility to performance-related injuries

• There is no ideal percent body fat for each sport

• Or is there?

Body Composition and Wellness (continued)

• Body composition, body Image, and emotional wellness

• Body image—a mental picture of your own body

• Body dysmorphic disorder—preoccupation with imagined defect in appearance

• Muscle dysmorphia—obsessed with idea that being muscular isn’t enough

Body Composition and Wellness (continued)• How do you feel about the social media pressures

to be thin or very muscular?

Figure 7-7 Average young women versus fashion models and Miss America (1920s-2000s)

Fat Facts• 1. Fat has different

colors.• When you think of fat,

you most likely think of the white stuff on your tummy, hips and thighs that stores energy until you need it.

• there's also brown fat, more prevalent in newborns that helps them keep body temperatures stable without shivering.

Fat Facts• 2. Not everybody has

brown fat. • However, brown fat is

limited in obese individuals

• adults have about 50 grams of brown fat that can burn energy equal to roughly 10 pounds of white fat a year.

• people start losing brown fat in their late 40s and early 50s, and he suspects this could be related to age-related obesity.

•

Fat Facts• 3. Fat keeps us warm, and

not just by insulating us.

• All fat cells -- not just brown ones -- can sense temperature directly, and they respond to cold by releasing their energy as heat

• 4. Exercise could change the behavior of your fat cells' DNA.

• The amount of fat your body carries is partly determined by genetics, but exercise could play a role in switching on or off certain genes that have to do with fat storage.

• six-month regimen of spinning or aerobics classes twice a week. At the end of the six months, the men had dropped weight and were healthier. But many of the genes in their fat cells had also been altered, some having to do with fat storage and the risks for developing obesity or diabetes.

Fat Facts5. Not all fat cells are

created equal. • Some obese people are

metabolically healthy, while others have metabolic diseases such as diabetes, high blood pressure and high cholesterol levels and it turns out you can see the

• fat cells of unhealthy obese people swell and lead to inflammation and fat storage on organs like the liver and heart.

• The fat cells in healthy obese people, are smaller and make new fat cells when more fat needs to be stored.

Healthy v. Unhealthy

Pause, Carmen Question!• “If a lack of sleep increases body fat, specifically

abdomen adipose tissue, can insomnia have even more drastic effects on fat accumulation across the entire body? I ask because I do have insomnia and I have had an increase in body fat over the past year. “

Fat Facts• 6. Fat cells need sleep,

too. • If you skimp on sleep, you

might be hurting your body fat's ability to respond to insulin= Insulin resistant!

• 8.5 hours in bed for four consecutive nights switched to 4.5 hours in bed for four consecutive nights with idential food intake (study)

• After four nights of short sleeping sessions, the fat cells' insulin sensitivity had decreased by 30 percent

Fat Facts• 7. APPLES V PEARS. • Love handles, flabby forearms

and double-chins; while these visible (and grab-able) signs of excess fat can be troubling, it's the visceral fat, or fat you can't see, that should be of more concern.

• Fat right under the skin, or subcutaneous fat, acts as our insulator and cushion in addition to an energy storage unit.• APPLE

• visceral fat, which is embedded deep within the abdomen, fills in the spaces between our organs and pumps out chemicals that can increase the risk of cardiovascular disease, hypertension and diabetes• PEAR