1. © 2010 Pearson Education, Inc. Chapter 15: Weight Management and Disordered Eating

2. © 2010 Pearson Education, Inc. The Status of Obesity in America  In the early 1960s, fewer than 32% of Americans were overweight  Today, 67% of Americans are overweight More than 33% of adults and 16% of children are obese  Americans spend over $45 billion annually on weight-loss solutions  Medical complications associated with overweight cost the U.S. health care system $92 billion annually

3. © 2010 Pearson Education, Inc. What Is Weight Management and Why Is It Important?  Weight management is maintaining body weight in a healthy range BMI 18.5–24.9  Underweight and overweight can both be of concern

4. © 2010 Pearson Education, Inc. What Is Weight Management and Why Is It Important?  Underweight increases risk for Low body protein and fat stores Depressed immune system  Overweight and obesity Can increase risk of numerous health problems Can expose individuals to increased social, educational, and economic disadvantages  Healthy People 2010 aims to reduce overweight and obesity in adults to less than 15% and to 5% in children and adolescents

6. © 2010 Pearson Education, Inc. Quick Review  Weight management means maintaining a healthy weight (BMI 18.5–24.9) to reduce risk of certain health problems  Both underweight and overweight are associated with increased health risks  Obesity and underweight are associated with negative social and psychological effects including discrimination, low self-esteem, depression, suicide, and alcohol and drug problems  Reducing overweight and obesity are two of the Healthy People 2010 national health objectives

7. © 2010 Pearson Education, Inc. How Do Fat Cells Form and Expand?  Growth of fat cells (adipocytes) occur in two ways Can expand to store more fat (hypertrophy) Once filled to capacity, stimulate the production of more fat cells (hyperplasia)

8. © 2010 Pearson Education, Inc. How Do Fat Cells Form and Expand?  Average adult has 30–50 billion adipocytes which hold 0.4–0.5 micrograms of fat each Adipocytes of obese individuals store 0.6–1.2 micrograms of fat per cell Weight loss leads to shrinking the size of adipocytes, but no change in the number of cells  Hyperplasia slows with age, but growth and production of fat cells continues throughout life

9. Figure 15.1 The Formation of Adipocytes

10. © 2010 Pearson Education, Inc. How Do Fat Cells Form and Expand?  Enzymes control the size of fat cells Lipoprotein lipase (LPL) increases lipogenesis Hormone-sensitive lipase (HSL) stimulates lipolysis  Heavier people have increased activity of LPL Men: LPL more active in visceral, abdominal fat cells Women: LPL activity higher in hips and thighs

11. © 2010 Pearson Education, Inc. Quick Review  The average adult body contains 30–50 billion adipocytes  When adipocytes reach their maximum capacity to store fat, new cells form  Obese individuals have more fat cells storing a greater quantity of fat  LPL and hormone-sensitive lipase are enzymes that influence the balance between lipogenesis and lipolysis  The activity of these enzymes differs in overfat and lean individuals and in men and women

12. © 2010 Pearson Education, Inc. How Is Food Intake Regulated?  Hunger and satiation are controlled by hormones that are produced in the brain and gastrointestinal tract  Appetite is the desire to eat food whether or not there is physical hunger; may be triggered by factors such as time of day, social occasions, emotions, or the sight or smell of food

13. © 2010 Pearson Education, Inc. Figure 15.2 How Is Food Intake Regulated?  Two regions within the hypothalamus of the brain control hunger and satiety Ventromedial nucleus Lateral hypothalamus

14. © 2010 Pearson Education, Inc. How Is Food Intake Regulated?  After a meal, satiety is triggered in the ventromedial nucleus Stretch receptors in the stomach signal fullness Cholecystokinin and peptide YY send feedback to the hypothalamus to increase satiety and decrease hunger Nutrient absorption triggers insulin release which also decreases hunger Leptin, produced by adipose tissue, both suppresses hunger and promotes energy expenditure

15. © 2010 Pearson Education, Inc. How Is Food Intake Regulated?  The lateral hypothalamus controls hunger Ghrelin, produced by the stomach, stimulates hunger during fasting or on a low-kilocalorie diet Neuropeptide Y is produced in the hypothalamus and activated by ghrelin; it stimulates hunger and LPL activity  In addition to hormones, certain macronutrients, especially protein, promote satiety and reduce food intake

16. © 2010 Pearson Education, Inc. Quick Review  Food intake is controlled by hunger, satiety, and appetite  Within the brain, the ventromedial nucleus controls satiety and the lateral hypothalamus controls hunger  Neuropeptides, hormones, and neural signals from the gastrointestinal tract and adipocytes communicate hunger and satiety to the hypothalamus  Leptin and ghrelin play key roles in triggering hunger and satiety, with ghrelin triggering hunger and leptin triggering satiation

17. © 2010 Pearson Education, Inc. Genetics in Obesity and Weight Management  Genetics can make the body more susceptible to weight gain or weight loss Genetic differences in the level or functioning of some hormones such as leptin and ghrelin Differing responses to environment and availability of food Different rates of nonexercise activity thermogenesis (NEAT) Genetic “set point” theory that individuals have a genetically established body weight and deviation from this point will stimulate changes in metabolism to reestablish the normal weight

18. © 2010 Pearson Education, Inc. Environment in Obesity and Weight Management  Environmental factors can increase appetite and decrease physical activity Gene-environment interaction – the interaction of genes and the environment increases risk of obesity in susceptible individuals Lack of time results in Americans turning to high-calorie convenience foods or dining out An abundant food supply and portion distortion result in people eating more Decreased physical activity and increased sedentary behavior means Americans are burning fewer calories

19. © 2010 Pearson Education, Inc. Quick Review  Genetic influences play a role in weight management including influencing the levels of the hormones leptin and ghrelin  Environmental factors, including lack of time, an abundant food supply, portion distortion, and lack of physical activity, encourage obesity

20. © 2010 Pearson Education, Inc. Figure 15.3 How Can You Lose Weight Healthfully?  Overweight individuals should aim to lose 10% of their body weight over 6 months  The keys to long-term weight management

22. Figure 15.5 The Volume of Food

23. How Can You Lose Weight Healthfully?  Devote 60 to 90 minutes daily to moderate-intensity physical activity to aid in weight loss, prevent weight gain

24. © 2010 Pearson Education, Inc. Quick Review  The keys to successful long-term weight loss include reducing daily kilocalorie intake, increasing physical activity, and changing behaviors  Meals of low-energy density, high-volume vegetables, fruits, and fiber along with lean protein and healthy oils promote satiety and reduce unplanned snacking  Daily physical activity facilitates weight loss  Changing unhealthy habits by removing certain environmental cues supports healthy eating habits

25. © 2010 Pearson Education, Inc. How Can Weight Loss Be Maintained?  Setting realistic weight goals is essential to prevent false hope syndrome and risk of dropping a weight-loss program  Weight cycling is thought to lead to problems such as hypertension, gallbladder disease, and elevated cholesterol  After weight loss, a person will have lower energy needs because there is less body weight to maintain; this is known as the “energy gap” phenomenon Increasing daily physical activity is the easiest way to close the energy gap and overcome weight loss plateaus  Some individuals with a BMI > 40 are candidates for extreme treatments to lose weight

26. © 2010 Pearson Education, Inc. Extreme Measures for Extreme Obesity  A very low-kilocalorie diet Is a short-term solution for individuals at high risk of disease related to obesity Requires vitamin and mineral supplementation and medical supervision  Weight-loss medications Sibutramine (Meredia) – suppresses appetite Orlistat (Xenical) – inhibits fat absorption

27. © 2010 Pearson Education, Inc. Extreme Measures for Extreme Obesity  Surgery Gastric bypass Gastric banding Liposuction

28. © 2010 Pearson Education, Inc. Quick Review  Setting realistic weight-loss goals will prevent the false hope syndrome associated with trying to achieve goal weight too quickly  Exercise improves muscle mass, prevents a decline in basal metabolism, and helps overcome weight loss plateaus  Eating less or exercising more helps close the energy gap following weight loss  For individuals with a BMI greater than 40, more extreme weight loss treatments may be indicated

29. © 2010 Pearson Education, Inc. What Is the Healthiest Way to Gain Weight?  Eat sufficient energy to meet basal needs plus fuel for the exercise needed to stimulate muscle synthesis  Focus on a variety of energy-dense, nutritious food choices  Eat larger portions at meals and energy-dense snacks during the day  Add at least 500 kilocalories daily for weight gain of about one pound per week  Regular exercise and resistance training stimulate muscle growth and help to avoid excess fat storage

30. Figure 15.7 More- and Less-Energy-Dense Food Choices

31. © 2010 Pearson Education, Inc. Quick Review  Weight gain can be as challenging and frustrating as trying to lose weight  People who want to gain weight need to consume additional kilocalories through energy-dense food to take in more energy than they expend  Increasing portion sizes and adding nutrient-dense snacks helps to increase total intake  Add resistance exercise to build muscle mass

32. © 2010 Pearson Education, Inc. What Is Disordered Eating?  Disordered eating describes abnormal and potentially harmful eating patterns  Eating disorders are psychological illnesses diagnosed by meeting specific criteria that include disordered eating behaviors and other factors  Eating disorders affect over 1 million U.S. individuals

34. © 2010 Pearson Education, Inc. Health Consequences of Disordered Eating  Health consequences of anorexia nervosa include Electrolyte imbalances Drop in heart rate and blood pressure, weakness and fatigue, hair loss Slowing of the digestive process Inadequate nutrient intake and possible deficiencies

35. © 2010 Pearson Education, Inc. Health Consequences of Disordered Eating  Health consequences of bulimia nervosa include Tears in the esophagus Tooth decay and gum disease from stomach acid Electrolyte imbalances Dehydration and constipation Impaired normal bowel function through laxative use

36. © 2010 Pearson Education, Inc. Eating Disorders Not Otherwise Specified  Binge eating disorder Characterized by recurrent episodes of binge eating without regard to physiological cues May eat for emotional reasons resulting in out-of-control feeling while eating and physical and psychological discomfort after eating May eat in secret and feel ashamed about their behavior Negative health effects are those associated with obesity such as high blood pressure, high cholesterol, heart disease, type 2 diabetes, and gallbladder disease

37. © 2010 Pearson Education, Inc. Eating Disorders Not Otherwise Specified  Night eating syndrome A person consumes a majority of daily kilocalories after the evening meal and wakes up during the night to eat Typically does not have an appetite during morning hours Is a unique combination of disordered eating, a sleep disorder, and a mood disorder Stress is a contributing factor to the development and continuation of the disorder May feel guilty, ashamed, or embarrassed while eating at night as well as the next morning Most often in young adults 18–30 years old

39. © 2010 Pearson Education, Inc. How Are Eating Disorders Treated?  Effective treatment requires a multidisciplinary team approach including Psychological professionals Medical professionals Nutrition professionals  As some eating disorders can be life-threatening, a physician should closely monitor treatment

40. © 2010 Pearson Education, Inc. How Are Eating Disorders Treated?  A Registered Dietitian can help someone with an eating disorder establish normal eating behaviors  Nutritional approaches include Meal planning Using food journals Identifying binge triggers, safe and unsafe foods Recognizing hunger and fullness cues  Full recovery from eating disorders is possible and most successful when the disorder is treated in the early stages

41. © 2010 Pearson Education, Inc. Quick Review  Disordered eating is characterized by an abnormal eating pattern  Eating disorders include disordered eating and other diagnostic criteria  Over 11 million Americans struggle with eating disorders  Eating disorders include anorexia nervosa, bulimia nervosa, binge eating or compulsive overeating, and night eating syndrome  Recovery is possible, particularly if treatment is sought in the early stages of the disorder

42. © 2010 Pearson Education, Inc. Putting It All Together  Maintaining a healthy body weight reduces the negative physical and psychological effects of obesity  Hunger and satiety are regulated by the hypothalamus of the brain through neuropeptides, hormones, and neural signals from the gastrointestinal tract and adipocytes  Both genetic and environmental factors influence obesity and weight management  Diet, physical activity, behavior modification are the keys to long-term weight management  Eating disorders include anorexia nervosa, bulimia nervosa, binge eating or compulsive overeating, and night eating syndrome  Treatment of eating disorders requires a multidisciplinary team approach