The document discusses body composition and techniques for measuring it such as BMI, bioelectrical impedance analysis, skinfold measurements, air displacement plethysmography, underwater weighing, and dual-energy x-ray absorptiometry. It addresses causes of obesity including biological factors like heredity and behavioral factors like overeating and physical inactivity. Strategies for fat loss discussed include dieting, physical activity, surgery, and avoiding unhealthy weight loss methods.

1. Healthy Weight
and Body Composition

2. BODY COMPOSITION
•Body composition is the ratio between fat and
fat-free mass
•Fat-free mass includes all tissues exclusive of fat
(muscle, bone, organs, fluids)
•Essential fat is necessary for normal biological
function
•Essential fat for men is 3% to 5% of total
weight; it is 8% to 12% percent for women

3. MEASURING BODY COMPOSITION

4. •Height/weight tables do not reflect body composition and
are poor instruments for weight-loss recommendations
•Body mass index (BMI) is the ratio of body weight in
kilograms to height in meters squared
•People with BMIs of 25 to 29.9 are considered
overweight; people with BMIs of 30 or higher are
considered obese
TECHNIQUES

5. BMI-Body Mass Index

6. • Healthy weight is defined as a body mass index (BMI) equal to or no more than 18.5
and no more than 24.9
• Overweight is defined as having a BMI between 25 and 29.9
• Obesity is defined as having a very high amount of body fat in relation to lean body
mass or a BMI or 30 or higher
• Adult obesity has grown from 13% in 1960 to 40% in 2012
• Children and adolescent ages 2-19 – 32% are obese
• 17% of children have a BMI of 30 or higher
• Americans are heavier because:
• Too little energy going out
• Too much energy going in
• America has become an obesogenic environment i.e. one that promotes increase
food intake

7. • Bioelectrical impedance analysis
• uses a low-level, single-frequency electric current to measure body
composition
• Skinfold measurements
• one of the most economical ways to measure body composition and,
when performed by skilled technicians, correlate well with hydrostatic
weighing
• Air-Displacement Plethysmography
• Uses air displacement rather than water displacement for assessing
body composition by sitting in the Bod Pod
MORE TECHNIQUES

8. •Underwater weighing is one of
the most accurate indirect
measurement techniques
•People with more muscle mass
weigh more in water than
those with less
Hydrostatic Weighing

9. •Dual-Energy X-Ray Absorptiometry
•bone mineral density, quantification of fat, and
lean tissue using very low exposures to radiation.
DEXA

10. ACHIEVING A HEALTHY WEIGHT
•At any given time, more than one-half of women and
one-fourth of men are on a diet
•For some people the weight obsession can lead to
serious body-image problems, including body
dysmorphic disorder (BDD)
•The number of people who would benefit from a fat-
loss program is at an all-time high
•Term weight loss should be replaced with the more specific
term fat- loss

11. OBESITY AND OVERWEIGHT
•Obesity is overfatness
•Obesity in men is defined as body fat equal
to or greater than 25% of total body weight
•Obesity in women is defined as body fat
equal to or greater than 35% of total body
weigh
•Overweight is excessive weight for height and
does not consider body composition

12. REGIONAL FAT DISTRIBUTION
•Most women store fat in the hips,
buttocks, thighs, and breasts (gynoid fat)
•Most men store fat in the abdomen,
lower back, chest, and nape of the neck
(android fat)
•Intra-abdominal fat is stored deep in the
abdominal cavity and carries a high risk
for cardiovascular diseases

13. ADIPOSE CELL DEPOSITS

14. DEVELOPMENT OF OBESITY
•Obesity occurs when the 30 to 40 million adipose (fat)
cells in the body increase in size (hypertrophy), number
(hyperplasia), or both
• Gender differences in fat storage
• Males- upper half of body (android)
• Females- lower half of body (gynoid)
• Biological factors that influence obesity are age, metabolism,
gender, disease, heredity, and set point

15. HEALTH ASPECTS OF OBESITY
• Coronary heart
disease
• Stroke
• Hypertension
• LDL cholesterol
• Diabetes II
• Psychological
distress
• Gallbladder
disease
• Osteoarthritis
• Sleep apnea
• Some cancers

16. OBESITY TRENDS AMONG U.S. ADULTS

18. CAUSES OF OBESITY
• Biological Theories
• Age, metabolism, gender, disease, heredity and set point, the body
internal signal for the level of fatness
• Two major biological explanations of obesity are heredity and
set point
• Heredity influences both body weight and body shape
• Leptin – hormone made in fat cells by a gene call OB
• leptin signals brain to suppress appetite – if missing or not functioning
brain does not get signal to stop eating

19. • The set point theory suggests that the body works to maintain a
certain weight no matter what a person does
• Sometimes referred to as Defended Weight
•Weight that body strives to attain when not on a diet or
participating in an exercise program – normal weight
•Body has internal set point for the weight it defends
• Physiological evidence to support the set point explanation
•As the energy intake is reduced, the blood concentration of
thyroid hormone falls and the metabolic rate slow

20. BEHAVIORAL THEORIES
• Behavioral explanations of obesity include
overeating, lack of exercise
• Overeating - consuming more calories than are
required by the body
• Most experts view high dietary fat intake as the
major factor in obesity
• Calories from fat appear to convert to body fat
more readily than calories from carbohydrates
and protein
• Portion size
• Fat grams and low-carbohydrate diets are of less
concern than the quantity of food eaten

21. OVEREATING AND INACTIVITY
• People cannot eat as much as they want
to just because a food is fat free
• Modern conveniences and labor-saving
devices have resulted in less physical
activity
• A sedentary lifestyle is partially
responsible for the obesity in America
• Physical exercise is vital for weight
maintenance

22. INACTIVITY
• Hypokinesis – physical inactivity or sedentary
lifestyle
• Some experts view lack of physical activity as the
distinguishing factor that separates the obese
from those of normal weight
• Exercise alone is not a major component in weight
loss, but it is the most important component in
weight gain

23. STRATEGIES FOR FAT LOSS
• The loss of one pound of body fat requires a deficit of
3500 calories
• A desirable long-term goal for losing weight is 1 to 2
pounds a week until 10% of total body weight is lost
• A six-month maintenance program should follow weight
loss before losing more
• Weight loss should be a combination of restricting
calories and increasing caloric expenditure

24. •the method of choice for most people to
lose weight
•Only 5% of dieters successfully lose and
maintain their weight loss for one year
•Weight cycling (yo-yo dieting) usually
results in a greater weight gain following
a loss period and increases the risk of
death
Dieting

25. •Caloric intake should not drop below 1200 per day for women or
1500 per day for men
•Popular Diets
•Potentially hazardous
•Characteristics of fad diets
•Promote quick results;
•focus on eating one type of food or
• excluding an entire food group,
•rarely emphasize permanent lifestyle changes

26. •Low fat diets
•Americans are consuming fewer fat calories but more total
calories and are getting heavier
•Very low calorie diets (VLCDs) have fewer than 800
calories a day and should be viewed as medical
intervention

27. • Overcompensatory eating is when the consumption of
low-fat foods leads to an increase in total calories
• Increases in portion sizes of foods in restaurants and
in the grocery contribute to greater food consumption
• Diet drugs offer only a temporary solution and side
effects can be deadly

28. • Bariatric surgery – surgery to reduce weight
• Gastroplasty –limits stomach size
• Popular term – stomach stapling
• Several variations of gastroplasty
• Considered a treatment for those individuals whose BMI is 40 or
greater
• men 100 pounds overweight
• Women 80 pounds overweight
• Liposuction – surgical removal of fat tissue
• Cosmetic procedure
Extreme Treatments

29. • Herbal remedies are unregulated and when
taken in large, concentrated doses should be
viewed as drugs
• The optimal approach to weight loss
combines mild caloric restriction with
regular physical activity
• Fasting and modified fasts can be harmful
especially if done for a prolonged period of
time

30. PHYSICAL ACTIVITY
• Physical activity and dieting should yield a daily
caloric deficit of 500 calories
•3500 caloric reduction to lose one pound of fat
•Exercise stimulates metabolism
•Metabolism affected by age, gender, nervous system
activity, endocrine glands, nutrition, sleep, fever, climate &
amount of muscle tissue

31. PHYSICAL ACTIVITY
• Basal metabolic rate (BMR) is the energy required to
sustain life when the body is rested and fasting
• Persons who are deconditioned need to start slowly
and progress gradually
• Increased muscle tissue raises BMR
• People who lose weight and keep it off almost always
exercise daily
• Low intensity exercise burns more fat calories

32. GUIDELINES
• To reduce risk of chronic diseases in adulthood: 30min of moderate
physical activity daily
• To prevent unhealthy weight gain in adulthood: 60 min of
moderate to vigorous physical activity on most days
• To sustain weight loss in adulthood: 60min moderate daily physical
activity

33. EATING DISORDERS
• Anorexia nervosa
• the refusal to maintain minimally normal weight for age and height.
• characterized by the refusal to eat
• Bulimia nervosa
• alternates bingeing with purging (Symptoms of disordered eating are also
serious
• Binge-eating disorder
• Consuming large amounts of food in one sitting
• Lack of control
• The Female AthleteTriad is common among young athletes
• Disordered eating, amenorrhea, osteoporosis

34. PRINCIPLES OF WEIGHT MANAGEMENT
• Avoiding an obsession with body
weight
• Avoiding fad diets
• Avoiding fasting and restrictive
dieting
• Avoiding volume eating
• Watching “hidden sugar”
• Developing a plan
• Set realistic goals
• Being physically active
• Making gradual lifestyle changes
• Avoiding diet pills
• Avoiding very-low calorie diets
• Avoid fasting
• Avoid skipping meals
• Remember weight maintenance may be
more appropriate than weight loss
• Consulting a nutritionist, physician, or
weight-loss program provider to help
develop a plan