1.  2010 Cengage-Wadsworth Chapter 9 Weight Management

2.  2010 Cengage-Wadsworth Ask Yourself 1.The less you weigh, the better it is for your health. 2.Obese people pay higher insurance premiums than thin people. 3.If you weigh too much according to the scales and the so-called ideal weight tables, you are too fat. 4.If you are too fat, it is because you eat too much. 5.Basal metabolism contributes only a small percentage of a person’s daily energy output.

3.  2010 Cengage-Wadsworth Ask Yourself 6.Probably the most important contributor to the obesity problem in our country is under activity. 7.Any food can make you fat, even carrot sticks, if you eat enough of it. 8.You can lose weight faster on a properly designed diet and exercise program than on a total fast. 9.Fad diets are popular because their followers achieve quick and permanent weight loss. 10.Anorexia nervosa is a disease in which a person has no appetite.

4.  2010 Cengage-Wadsworth A Closer Look at Obesity Bodies come in many shapes and sizes. Which are healthy?

5.  2010 Cengage-Wadsworth A Closer Look at Obesity Trends in Prevalence of Overweight and Obesity among Children and Adults, United States, 1988–2004

6.  2010 Cengage-Wadsworth A Closer Look at Obesity Many factors including genetics influence body weight. Excess energy intake and physical inactivity are the leading causes of overweight and obesity. They also represent the best opportunities for prevention and treatment.

7.  2010 Cengage-Wadsworth A Closer Look at Obesity Trends resulting in poor nutrition and decreased activity: Food portion sizes and obesity rates have grown in parallel. Vending machines selling soft drinks, high-fat snacks, and sweet snacks are common in schools and workplaces. Adults spend more time in sedentary activities, such as watching television, computing, or commuting. Children watch 12 to 14 hours of television a week and spend 7 hours playing video games. Schools offer fewer physical education classes for children. Increasing numbers of families live in communities designed for car use, unsuitable and often unsafe for activities such as walking, biking, and running.

8.  2010 Cengage-Wadsworth A Closer Look at Obesity Overweight: conventionally defined as weight between 10% and 20% above the desirable weight for height, or a body mass index (BMI) of 25.0 through 29.9. Obesity: conventionally defined as weight 20% or more above the desirable weight for height, or a BMI of 30 or greater. Fact: Obesity rates are higher than ever. Currently, 67% of adults and approximately 17% of children and adolescents in the U.S. are either overweight or obese— exceeding their healthy weight range. Annual cost of overweight and obesity exceeds $117 billion a year. Direct costs (treatment) Indirect costs (lost productivity, disability, morbidity & mortality)

9.  2010 Cengage-Wadsworth The Epidemic of Obesity among U.S. Adults

10. Fig. 9-2, p. 293 19912004 19952007 2000 No data <10% 10%-14% 15%-19% 20%-24% 25%-29% ≥30%

11.  2010 Cengage-Wadsworth Problems Associated with Weight Some people can weigh too much while others weigh to little. Underweight: weight 10% or more below the desirable weight for height, or a BMI less than 18.5. Problems of underweight individuals: Possess minimal fat stores. Could be at a disadvantage when energy reserves are needed. Menstrual irregularity, infertility, osteoporosis.

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13. What Is a Healthful Weight? Problems of defining a healthful weight are many. For long-distance runners, unneeded pounds are a disadvantage. For swimmers, fat contributes to their buoyancy and insulates them against the cold. Dancers and models may value thinness so highly that to attain it, they compromise their health. What range is compatible with wellness and long life?

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15. What Is a Healthful Weight? Body Weight versus Body Fat Two people of the same sex, age, and height may both weigh the same, yet one may be too fat and the other too thin. The difference lies in their body composition. Obesity must be defined by amount of body fat rather than by weight. The health risks for obesity refer to people who are overfat. Desirable measures for percent body fat: Men 12%-20% (overfat would be >25%) Women 20%-30% (overfat would be >33%)

16.  2010 Cengage-Wadsworth What Is a Healthful Weight? Measuring Body Fat Body fatness is hard to measure. One very accurate way is to measure the body’s density. Weight divided by volume Lean tissue is more dense than fat tissue. Underwater weighing or hydrostatic weighing measures the amount of water displaced.

17.  2010 Cengage-Wadsworth What Is a Healthful Weight? Measuring Body Fat Body density can more easily be determined by air displacement methods. The BodPod measures the volume of air displaced by a person when seated in a sealed device of known volume.

18.  2010 Cengage-Wadsworth What Is a Healthful Weight? Measuring Body Fat Skinfold Test: Using a caliper to measure the thickness of a fold of fat, the measurement is then applied to a standard table to give a fair approximation of total body fat. The fatfold test gives a fair approximation of body fat.

19.  2010 Cengage-Wadsworth What Is a Healthful Weight? Measuring Body Fat Dual energy X-ray absorptiometry (the DEXA test) can yield an accurate image of the body’s fat-free tissue and total fat content. This test can be costly.

20.  2010 Cengage-Wadsworth What Is a Healthful Weight? Measuring Body Fat Bioelectrical impedance: estimation of body fat content made by measuring how quickly electrical current is conducted through the body.

21.  2010 Cengage-Wadsworth What Is a Healthful Weight? Distribution of Fat Central obesity: excess fat on the abdomen and around the trunk. “Apple-shaped” body Strong risk factor for type 2 diabetes, heart disease, hypertension, and other problems. Peripheral obesity: excess fat on the arms, thighs, hips, and buttocks. “Pear-shaped” body There are health implications to how body fat is distributed.

22.  2010 Cengage-Wadsworth What Is a Healthful Weight? Weighing In for Health A person’s health risk is dependent on three factors: Body weight Amount and location of body fat Current health status Body mass index: an index of a person’s weight in relation to height that correlates with total body fat content. BMI does not account for: Location of fat in the body Muscular people with a low percentage of body fat may have a high BMI

23.  2010 Cengage-Wadsworth What Is a Healthful Weight? Waist circumference measurement provides information about the distribution of fat in the abdomen. Disease risk rises when waist circumference exceeds: 35 inches in women 40 inches in men

24.  2010 Cengage-Wadsworth Benefits of Using BMI: BMI correlates strongly with body fatness and risk of disease and death.

25.  2010 Cengage-Wadsworth Healthy Weight

26.  2010 Cengage-Wadsworth What Is a Healthful Weight?

27.  2010 Cengage-Wadsworth What Is a Healthful Weight? Cautions in Using BMI: May overestimate body fat in athletes and underestimate body fat in adults over 65. A muscular person, such as this body builder, often has a low percentage of body fat but a high BMI.

28.  2010 Cengage-Wadsworth Energy Balance

29.  2010 Cengage-Wadsworth Energy Balance The body expends most of its energy on basal metabolism—maintaining basic physiological processes such as breathing, heartbeat, and other involuntary activities. The second largest amount of energy is expended for voluntary physical activities— an amount that will vary by activity level. A minor amount of energy is also used for the thermic effect of food—the energy needed to digest, absorb, and process the food you eat. How the Body Expends Energy

30. Fig. 9-4, p. 299 Thermic effect of food 5%–10% Basal metabolism 60%–65% Physical activity 25%–35%

31.  2010 Cengage-Wadsworth Energy Balance Basal metabolism: the sum total of all the chemical activities of the cells necessary to sustain life, exclusive of voluntary activities—that is, the ongoing activities of the cells when the body is at rest. Basal metabolic rate (BMR): the rate at which the body spends energy to support its basal metabolism. The BMR accounts for the largest component of a person’s daily energy (calorie) needs.

32.  2010 Cengage-Wadsworth Energy Balance To increase your metabolic rate, make exercise a daily habit. Body composition influences metabolic rate. Weight training can help shift your body composition toward more lean tissue, thereby speeding up your metabolism.

33.  2010 Cengage-Wadsworth Causes of Obesity Genetics Set-point theory: the theory that the body tends to maintain a certain weight by adjusting hunger, appetite, and food energy intake on the one hand and metabolism (energy output) on the other so that a person’s conscious efforts to alter weight may be foiled. An identified gene—named ob (for obese). Appears to produce a hormone called leptin (Greek word for slender). It has been reported that as body fat stores increase, blood leptin increases.

34.  2010 Cengage-Wadsworth Causes of Obesity Genetics Fat cell theory: states that during the growing years, fat cells respond to overfeeding by producing additional fat cells; the number of fat cells eventually becomes fixed, and overfeeding from this point on causes the body to enlarge existing fat cells. Fat cells of obese people contain higher levels of the enzyme lipoprotein lipase (LPL), which determines the rate at which adipose cells store fat. Lipoprotein lipase (LPL): an enzyme located on the surfaces of fat cells that enables the cell to convert blood triglycerides into fatty acids and glycerol to be pulled into the cell for reassembly and storage as body fat. The larger the fat cell (and the greater the number of fat cells), the more LPL and the more easily the body can pull triglycerides into fat cells for storage.

35.  2010 Cengage-Wadsworth Causes of Obesity Environment External cue theory: the theory that some people eat in response to such external factors as the presence of food or the time of day rather than to such internal factors as hunger.

36.  2010 Cengage-Wadsworth Causes of Obesity A Closer Look at Eating Behavior Hunger: the physiological drive to find and eat food, experienced as an unpleasant sensation. Appetite: the psychological desire to find and eat food, experienced as a pleasant sensation, often in the absence of hunger. Satiety: the feeling of fullness or satisfaction that people feel following a meal.

37.  2010 Cengage-Wadsworth Causes of Obesity Hypothalamus (high-poh- THALL-ah-mus): a part of the brain that senses a variety of conditions in the blood, such as temperature, salt content, and glucose content, and then signals other parts of the brain or body to change those conditions when necessary. Arousal: as used in this context, heightened activity of certain brain centers associated with excitement and anxiety.

38. p. 303 Brain stem Thalamus Hypothalamus Spinal cord

39.  2010 Cengage-Wadsworth Causes of Obesity Eating behaviors many be a response to hunger, appetite, and other complex human sensations. Stress may also promote the accumulation of body fat. Probably the most important contributor to obesity is underactivity.

40.  2010 Cengage-Wadsworth Weight Gain and Loss Changes in body weight can reflect shifts in fat, fluid, bone minerals, and lean tissues (e.g. muscles). Most quick weight- loss diets promote large losses of fluid with little or no real loss of body fat.

41.  2010 Cengage-Wadsworth Weight Gain and Loss Weight Gain When you eat more calories than you need, where does this excess go in your body? The energy nutrients… carbohydrate fat protein …contribute to body stores

42.  2010 Cengage-Wadsworth Weight Gain and Loss Feasting: The person is storing energy

43. Fig. 9-5a, p. 305 A. When a person overeats (feasting): Carbohydrate Liver and muscle glycogen stores Body fat stores Food component: is broken down in the body to: and then stored as: Fat Fattyacids Glucose Aminoacids Fat after losing nitrogen in urine Protein (first used to replace body proteins)

44.  2010 Cengage-Wadsworth Weight Gain and Loss Fasting: The person is drawing on stored energy

45. Fig. 9-5b, p. 305 B. When a person draws on stores (fasting): Glucose Storage compound: is broken down in the body to: and then used for: Body fat stores Energy Liver and muscle glycogen stores Fattyacids

46.  2010 Cengage-Wadsworth Weight Gain and Loss Fasting: The person is in ketosis

47. Fig. 9-5c, p. 305 Glucose C. If the fast continues beyond glycogen depletion: Body protein Lose nitrogen in urine Ketonebodies Energy Body fat Aminoacids Body component: is broken down in the body to: and then used for: Fattyacids

48.  2010 Cengage-Wadsworth Weight Gain and Loss Ketosis (kee-TOE-sis): an adaptation of the body to prolonged (several days’) fasting or carbohydrate restriction. Body fat is converted to ketones, which can be used as fuel for some brain cells. Indirectly, the nervous system begins to feed on the body’s fat stores and reduces the need for glucose. This spares the muscle and lean tissue from being devoured and prolongs starvation.

49.  2010 Cengage-Wadsworth Weight Gain and Loss Ketosis May be harmful by upsetting the acid-base balance of the blood. The body’s lean tissue continues to be lost at a rapid rate. The body becomes conservative and slows the process of metabolism. Requires even fewer calories

50.  2010 Cengage-Wadsworth Diet Confusion: Weighing the Evidence Dieting is big business in the United States. Diets work because people limit their food consumption. Although most diets can provide a weight loss in the short term, few people can lose weight and keep it off. Some diets may be harmful.

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53. Weight Gain and Loss Evaluating Diets Systematically eliminates groups of foods. Probably lacking in nutrients. Hard to adhere to the eating plan. Encourages specific supplements of foods only available from selected distributor. May contain harmful or unproven ingredients. Touts magic or miracle foods that burn fat. The only way to “burn” fat is to increase physical activity or decrease the amount of calories consumed. Promotes bizarre quantities of one food or type of food. Not good advice, considering human nutritional needs.

54.  2010 Cengage-Wadsworth Weight Gain and Loss Evaluating Diets Has a rigid menu No one diet plan will work for everyone. Promotes specific food combinations. Needlessly restricts dietary intake and choices. Promises weight loss of more than two pounds per week. A safe weight loss goal = 0.5-2.0 pounds/week. Provide warnings for people with health conditions such as diabetes and hypertension. Does the program encourage/promote physical activity?

55.  2010 Cengage-Wadsworth Weight Gain and Loss Evaluating Diets Does the program encourage an intake very low in calories? Designed for persons with severe obesity or health problems. Needs vitamin and mineral supplementation. Should be medically supervised for adverse health effects. Needs dietary counseling before program ends.

56.  2010 Cengage-Wadsworth Weight Gain and Loss Drugs and Weight Loss The search is on to find a safe and effective drug solution to obesity. The ideal drug should: Be safe and effective for long-term use. Free of undesirable side effects & abuse potential. Effective at reducing body fat. The successful drug should be combined with lifestyle changes including a healthy diet and exercise.

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58. Weight Gain and Loss Surgery and Weight Loss Surgery may be an option for people who cannot lose weight by traditional means and are severely obese. Three common types of surgery include: 1.Gastroplasty (stomach stapling) 2.Gastric bypass 3.Gastric banding

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60. Fig. 9-6a, p. 312 In gastric bypass (Roux-en-Y) operations, a small pouch near the top of the stomach is created with staples or a plastic band and connected directly to the middle portion of the small intestine (jejunum). Surgical staples Small pouch Esophagus Jejunum Stomach Large intestine Duodenum Jejunum Bypassed stomach

61. Fig. 9-6b, p. 312 Gastric banding reduces the size of the stomach by using an adjustable silicone band or cuff near the top of the stomach to create a pouch that fills quickly and empties slowly. The inflatable band is connected to an access port placed close to the skin, allowing surgeons to tighten or loosen it to meet an individual’s needs. Esophagus Jejunum Large intestine Duodenum Stomach Band Small stomach pouch

62.  2010 Cengage-Wadsworth Weight Gain and Loss Surgery and Weight Loss Common side effects of surgical interventions include: Nausea, vomiting, diarrhea, heartburn, abdominal pain, and band slippage or pouch enlargement. More severe effects include: complications during surgery, infections and death.

63.  2010 Cengage-Wadsworth Weight Gain and Loss Surgery and Weight Loss Cosmetic surgery approaches include: Liposuction: a type of surgery (also called lipectomy) that vacuums out fat cells that have accumulated, typically in the buttocks and thighs. Surgery is appropriate in some instances. After surgery, a changed appearance does not guarantee changed eating habits, a better personality, reduced interpersonal conflicts, or any other improvements in the quality of one’s life.

64.  2010 Cengage-Wadsworth Successful Weight-Loss Strategies The secret is a sensible (not to say easy) three-pronged approach involving: 1.Healthful eating habits 2.Exercise 3.Behavior change Such an approach takes tremendous dedication. Many of those who complete weight-loss programs lose about 10% of their body weight, only to regain two- thirds of it back within 1 year and almost all of it back within 5 years.

65.  2010 Cengage-Wadsworth Successful Weight-Loss Strategies Personalize Your Weight-Loss Plan Find the plan that is right for you. Think of it as an eating plan that you will adopt for life. A calorie deficit of 500 calories/day for seven days is enough to lose one pound of body fat a week. Spending an extra 250 calories per day by exercising will increase the calorie deficit.

66.  2010 Cengage-Wadsworth Successful Weight-Loss Strategies Aim for gradual weight loss. Expect to reach a plateau. Aim for a positive gain in lean body mass. Weight loss and bone health. Include adequate calcium and weight- bearing exercise. Adopt a physically active lifestyle.

67.  2010 Cengage-Wadsworth Never Say Diet 1.Adopt a nondiet approach to weight loss. 2.Set achievable goals. 3.Focus on health rather than appearance.

68.  2010 Cengage-Wadsworth Eating Plan Strategies 1.Get personally involved. 2.Adopt a realistic plan, and then keep track of calories. 3.Make the eating plan adequate. 4.Emphasize high nutrient density. 5.Individualize. Eat foods you like. 6.Stress “dos,” not “don’ts.” 7.Eat regular meals. 8.Take a positive view of yourself. 9.Visualize a changed future self. 10.Take well-spaced weighings to avoid discouragement.

69.  2010 Cengage-Wadsworth Successful Weight-Loss Strategies Sample Balanced Weight-Loss Diets Using the MyPyramid Food Guide

70.  2010 Cengage-Wadsworth Strategies for using exercise for weight control 1.Make it active exercise; move your muscles. 2.Think in terms of quantity, not speed. 3.Exercise informally, in daily routines.

71.  2010 Cengage-Wadsworth Weight-Gain Strategies The healthful way to gain weight is to build yourself up by patient and consistent training while eating nutritious foods containing enough calories to gain weight. Choose calorie-dense snacks. Eat more frequently. Spend more time eating each meal: Start with the calorie-dense food first, finish with dessert. Eat regular, balanced meals. Eat more food and add extra calories.

72.  2010 Cengage-Wadsworth Examine your options. Take the edge off hunger with an appetizer… Make specific requests: reduced and fat-free dressings… Ask for entrees to be broiled, baked grilled, steamed or roasted… Request fresh fruit for dessert… Hold the sauce or order red sauces rather than white… Inquire about preparation… Downsize your order. Order a special omelet: egg substitute... Watch out for overindulgence Take time to enjoy your meal… Aiming for a Healthy Weight

73.  2010 Cengage-Wadsworth Eating Well on the Run Sandwich Shop: Fresh sliced veggies in a pita with low-fat dressing… Rotisserie Chicken: Chicken breast (remove skin), steamed vegetables… Fast Food: Grilled chicken breast sandwich (no sauce)… Salad Bars: Broth-based soups, fresh greens, low- fat dressing… Asian Take-Out: Wonton soup, steamed vegetable mixtures over rice or noodles… Pizza Night: Choose flavorful, low-fat toppings such as peppers, onions…

74.  2010 Cengage-Wadsworth Breaking Old Habits Behavior modification – a process developed by psychologists for helping people make lasting behavior changes.

75.  2010 Cengage-Wadsworth Elements of Behavior Change 1.Precontemplation: You need to change, but you’re not yet ready to accept that fact. 2.Contemplation: You want to change, but you’re not sure how. 3.Preparation: You gain knowledge to set up a plan of action for change. 4.Action: You jump in and “just do it.” 5.Maintenance: You work on sticking to your plan of action. 6.Termination: You have achieved lasting change and experience few, if any, temptations or relapses.

76.  2010 Cengage-Wadsworth Continued Motivation Persist long enough to experience the rewards, such as improved self-image and enhanced self-esteem. Remember the price of the old behavior. Keep in mind where you started. Tune in to the benefits of the new behavior.

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78. Addressing Overweight in Children The increasing prevalence of overweight is now the most important public health challenge in the U.S. The number of overweight children in the U.S. has tripled. Increases are greater among Hispanics and African Americans and are greater in the South.

79.  2010 Cengage-Wadsworth Addressing Overweight in Children The same adult diseases associated with overweight adults, such as type 2 diabetes, high blood lipids, high blood pressure, and gallbladder disease are appearing in kids. Overweight children are at risk for injury to weight-bearing joints, decreased quality of life, depression, poor self-esteem, respiratory problems, and sleep disturbances.

80.  2010 Cengage-Wadsworth Addressing Overweight in Children Helping Children Learn Good Habits Parents can set good examples. Discourage eating while watching TV and doing homework. Eat meals together as a family and keep fast- food meals to a minimum. Encourage children to eat only when hungry. Limit high-fat or high-sugar foods. Include children in food preparation.

81.  2010 Cengage-Wadsworth The Eating Disorders Eating disorder: general term for several conditions: Anorexia nervosa Bulimia nervosa Binge-eating disorder …that exhibit an excessive preoccupation with: Body weight Fear of body fatness Distorted body image

82.  2010 Cengage-Wadsworth For many people with anorexia nervosa, a full day’s diet may consist of no more than 3 or 4 items. The Eating Disorders Anorexia nervosa: Literally “nervous lack of appetite,” a disorder (usually seen in teenage girls) involving self- starvation to the extreme. an = without orexis = appetite

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84. The Eating Disorders Bulimia nervosa, bulimarexia (byoo- LEE-me-uh, byoo-lee-ma- REX-ee-uh): binge eating (literally, “eating like an ox”). Combined with an intense fear of becoming fat and usually followed by self-induced vomiting or the taking of laxatives. buli = ox

85.  2010 Cengage-Wadsworth The Eating Disorders Bulimia nervosa Two types: Purging type: the person regularly engages in self- induced vomiting or the misuse of laxatives, diuretics, or enemas. Nonpurging type: the person uses other behaviors, such as fasting or excessive exercise, but does not regularly engage in self-induced vomiting or the misuse of laxatives, diuretics, or enemas.

86.  2010 Cengage-Wadsworth The Eating Disorders Binge-eating disorder: an eating disorder characterized by uncontrolled chronic episodes of overeating (compulsive overeating) without other symptoms of eating disorders. Typically, the episodes of binge eating occur at least twice a week on average for a period of six months or more.

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88. The Eating Disorders Disordered eating: eating food as an outlet for emotional stress rather than in response to internal physiological cues. Unspecified eating disorders: some people suffer from unspecified eating disorders; that is, they exhibit some but not all of the criteria for specific eating disorders.

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