1. Achieving and Maintaining a Healthful Body Weight13
Achieving and Maintaining a Healthful Body Weight 1

2. What Is a Healthful Body Weight?
Appropriate for age, physical development
Maintained without constant dieting
Based on genetic background and family history of body shape and weight
Compatible with normal blood pressure, lipid levels, and glucose tolerance
Promotes good eating habits and allows for regular physical activity
Acceptable to you 2

3. What Is a Healthful Body Weight?
Underweight: having too little body fat to maintain health
Overweight: having a moderate amount of excess body fat 3

4. What Is a Healthful Body Weight?
Obese: having an excess of body fat that adversely affects health
Morbid obesity: body weight exceeding 100% of normal, a very high risk for serious health consequences 4

5. Evaluating Body Weight
Determining if a person’s body weight is healthful should include:
Determining the body mass index (BMI)
Measuring body composition
Assessing the pattern of fat distribution 5

6. Body Mass Index
Expresses the ratio of a person’s weight to the square of his or her height
BMI = weight (kg)/height (m)2
BMI = [weight (lbs)/height (inches)2] × 703
BMI values below 18.5 or above 30 have increased health risks
Not an indication of body composition 6

9. Fat Distribution Pattern
Apple-shaped fat patterning—upper body
Increased risk for chronic diseases
Men tend to store fat in the abdominal region
Pear-shaped fat patterning—lower body
No significant increased chronic disease risk
Women tend to store fat in the lower body 9

11. Fat Distribution Pattern
Abdominal fat increases risk for chronic disease
Waist-to-hip ratio
Men: waist-to-hip ratio higher than 0.90
Women: waist-to-hip ratio higher than 0.80
Waist circumference
Men: above 40 in. (or 102 cm)
Women: above 35 in. (or 88 cm) 11

13. Body Composition Measure body fat and lean body mass by
Underwater weighing
Skinfold measurements
Bioelectric impedance analysis
Near-infrared reactance
Dual-energy x-ray absorptiometry (DXA)
Bod Pod™ 13

16. Gaining or Losing Weight
Weight gain or loss depends on
Energy intake vs. energy expenditure
Genetic factors
Childhood weight
Behavioral factors
Social factors 16

17. Energy Balance Energy balance equation
Energy intake = energy expenditure
Energy intake is kcal from food, beverages
Energy expenditure is energy expended at rest and during physical activity 17

19. Energy Intake Calculating the energy that is in a particular food
Carbohydrate is 4 kcal/g
Protein is 4 kcal/g
Fat is 9 kcal/g
Alcohol is 7 kcal/g
1 cup of quick oatmeal has 142 kcal
6 grams protein × 4 kcal/gram = 24 kcal
25 grams carbohydrate × 4 kcal/gm = 100 kcal
2 grams fat × 9 kcal/gram = 18 kcal
Total kcal = 24 kcal kcal + 18 kcal = 142 kcal 19

20. Energy Intake
When total daily energy intake exceeds the amount of energy expended, weight gain results
An excess intake of approximately 3,500 kcal will result in a gain of 1 pound
Without exercise, this gain will likely be fat 20

21. Energy Expenditure
Energy is expended to maintain basic body functions and to perform activities
Total 24-hour energy expenditure is composed of three components:
Basal metabolic rate (BMR)
Thermic effect of food (TEF)
Energy cost of physical activity 21

23. Energy Expenditure
Direct calorimetry is a method that measures the amount of heat the body releases
Indirect calorimetry estimates energy expenditure by measuring oxygen consumption and carbon dioxide production 23

25. Basal Metabolic Rate (BMR)
Energy expended to maintain basal (resting) functions of the body
Includes respiration, circulation, maintaining body temperature, new cell synthesis, secretion of hormones, and nervous system activity
Primary determinant of BMR is the amount of lean body mass 25

28. Energy Expenditure Thermic effect of food (TEF)
Energy expended to process food
About 5−10% of the energy content of a meal
Energy cost of physical activity
About 15−35% of total daily energy output 28

30. Genetic Factors Influence height, weight, body shape, metabolic rate
About 25% of one’s body fat is accounted for by genetic influences
Different ideas have been suggested to explain the impact of genetics on body fat
Thrifty gene theory
Set-point theory 30

32. Thrifty Gene Theory
Proposes that a gene (or genes) causes people to be energetically thrifty
People with this gene expend less energy than other people
Protects from starvation during times of extreme food shortages
A “thrifty gene” has not been identified 32

33. Set-Point Theory
Suggests that body weight stays within a narrow range (set point)
Compensates for changes in energy balance and keeps a person’s weight at his or her set point 33

34. Composition of the Diet
Theory states that overeating dietary fat promotes storage as adipose tissue
Overeating carbohydrate or protein:
Used for energy, storage, or tissue building
Smaller amount of the excess stored as fat
Also leads to weight gain
Important to maintain a balanced diet combining fat, carbohydrate, and protein
Reading Labels 34

35. Physiologic Factors Hunger and satiety
Proteins affect the regulation of appetite and storage of body fat
Leptin acts to reduce food intake
Ghrelin stimulates appetite
Peptide YY (PYY) decreases appetite
Uncoupling proteins in brown adipose tissue increase energy expenditure 35

36. Physiologic Factors Increase satiety (or decrease food intake)
Hormones—serotonin, cholecystokinin (CCK)
Increase in blood glucose levels after meal
Stomach expansion
Nutrient absorption from the small intestine
Decrease satiety (or increase food intake)
Hormones—beta-endorphins
Neuropeptide Y
Decreased blood glucose levels 36

37. Cultural and Economic Factors
Religious beliefs
Learned food preferences
Fast-food culture
Sedentary lifestyle
Economic status
Access to healthcare 37

38. Psychologic and Social Factors
Appetite: psychological drive to eat
Meal timing and size: portion distortion
Sight and fragrance of foods
Mood, depression
Barriers to physical activity
Technological lifestyle
Social pressures 38

39. Achieve and Maintain Healthful Weight
Healthful weight change requires
Gradual change in energy intake
Regular and appropriate physical activity
Behavior modification techniques
Tips
Avoid fad diets
Achieve negative energy balance
ABC Video Fad Diets 39

41. Weight-Loss Diets
Moderate-fat, high-carbohydrate, moderate- protein diets
Balanced in nutrients: 20−30% calories from fat, 55−60% from carbohydrate, 15−20% from protein
Weight Watchers, Jenny Craig, DASH diet, and the USDA MyPyramid
Gradual weight loss (1−2 pounds per week)
Typical energy deficits = 500−1,000 kcal per day 41

42. Weight-Loss Diets High-fat, low-carbohydrate, high-protein diets
55–65% of total energy intake as fat and less than 100 g of carbohydrate per day
Dr. Atkins’ Diet Revolution, Protein Power
Cause ketosis, which will decrease blood glucose and insulin levels and reduce appetite
Concerns about long-term compliance, potential health risks, and side effects 42

43. Weight-Loss Diets Low-fat and very-low-fat diets
About 11−19% of total energy as fat, while very- low-fat-diets contain less than 10%
Dr. Dean Ornish’s Program for Reversing Heart Disease and The New Pritikin Program
Emphasize complex carbohydrates and fiber
Regular physical activity is a key component
Lower LDL cholesterol, triglyceride, glucose, and insulin levels, and lower blood pressure 43

44. Achieve and Maintain Healthful Weight
Set realistic and achievable goals that are:
Specific
Reasonable
Measurable
ABC Video Crash Diet
ABC Video Meal Replacements 44

45. Achieve and Maintain Healthful Weight
Follow recommended serving sizes
Reduce high-fat and high-energy food intake
Consume foods that are relatively low in energy density
Participate in regular physical activity
Incorporate appropriate behavior modifications into daily life 45

47. Weight-Loss Medications
Used only with a physician’s supervision
Long-term safety and efficacy explored
Sibutramine (Meridia): reduces appetite
Orlistat (Xenical): inhibits fat absorption
Should only be used if a person has
A BMI of 30 kg/m2
A BMI of 27 kg/m2 and other health risk factors 47

48. Dietary Supplements
Dangerous or ineffective supplements can be marketed and sold without meeting the FDA’s strict safety and quality standards
Insufficient evidence to support their use
Stimulants speed up metabolic processes; are controversial; and may be dangerous
Caffeine, phenylpropanolamine (PPA), and ephedra 48

49. Safe and Effective Weight Gain
Underweight: BMI of less than 18.5 kg/m2
Limit fat: <30% of total energy intake
Eat 500 to 1,000 extra kcal/day
Eat frequently throughout the day
Avoid tobacco (depresses appetite and increases BMR)
Exercise regularly with resistance training 49

50. Protein Supplements
Include amino acid supplements, anabolic steroids, and androstenedione
Do not enhance muscle gain or result in improvements in strength
Cause major health problems: unhealthful changes in blood cholesterol, mood disturbances 50

51. Overweight BMI between 25 and 29.9 kg/m2
Health risks: high blood pressure, heart disease, type 2 diabetes, sleep disorders
Many overweight people will become obese
Recommend healthful eating and regular physical activity to prevent additional weight gain, achieve a healthful weight, support long- term health
Increase in Obesity Rates in the United States 51

53. Obesity and Morbid Obesity
Obesity: BMI from 30 to 39.9 kg/m2
Morbid obesity: >100% normal weight
Considered an epidemic in the United States
Linked to many chronic diseases:
Hypertension
Dyslipidemia
Diabetes
Heart disease
Stroke 53

54. Metabolic Syndrome
A cluster of factors increases risk for heart disease, type 2 diabetes, and stroke:
Abdominal obesity (waist circumference >40 inches for men, 35 inches for women)
Triglyceride levels (>150 mg/dL)
HDL cholesterol levels (<40 mg/dL in men and 50 mg/dL in women)
Blood pressure (>130/85 mm Hg)
Fasting blood glucose >100 mg/dL 54

55. Obesity: Multifactorial Disease
Genetic and physiologic factors
Childhood obesity linked to adult obesity
Critical periods might increase risk
Gestation and early infancy
Period of weight gain (adiposity rebound) that occurs between 5 and 7 years of age
Adolescence (or puberty) 55

56. Obesity Treatment Low-calorie diet and regular exercise
Prescription medications
Surgery
Vertical banded gastroplasty
Gastric bypass surgery
Gastric banding
Liposuction
ABC Video Gastric Bypass Surgery 56