Chapter 6 lecture outline
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This document discusses managing weight and eating disorders. It begins by noting the rise in overweight and obesity rates in America over the past 30 years. It then discusses healthy weight ranges according to BMI and other measures. Several major health risks of excess weight are outlined, including increased risks of diabetes, heart disease, and some cancers. The document also examines eating disorders like anorexia nervosa, bulimia nervosa, binge eating disorder and discusses their prevalence, especially among college students and athletes. Lastly, it provides guidance on maintaining a healthy lifestyle through diet, exercise and developing a positive relationship with food.
Chapter 6 lecture outline
- 1. Chapter 6 – Managing Your Weight 6 Managing Your Weight LectureOutline I. Weight in America A. Introduction 1. Over the past 30 years, the proportion of Americans considered overweight or obese has steadily increased. 2. The prevalence of obesity among women has remained relatively stable, at about 35 percent, since 2000, but the prevalence among men has increased from 27.5 percent to 35.5 percent. B. Weight on Campus 1. Only about 5 percent of students gain the legendary “freshman 15.” According to a recent estimate, the average is about 11 pounds. 2. According to the National College Health Assessment, approximately one-third of college students are overweight or obese. II. What is a Healthy Weight? A. Body Mass Index (BMI) 1. BMI, a ratio between weight and height, is a mathematical formula that correlates with body fat. a. A healthy BMI ranges from 18.5 to 24.9. b. BMI of 25 or greater defines overweight and marks the point at which excess weight increases the risk of disease. c. A BMI of 30 or greater defines obesity and marks the point at which excess weight increases the risk of death. d. A BMI between 35 and 39.9 means increased risk of premature death. e. A BMI of 40 or higher indicates class 3 or severe obesity, a truly life- threatening condition. B. Waist Circumference 1. The general guideline is that a waist measuring more than 35 inches in a woman or more than 40 inches in a man signals greater health risks. C. Waist-to-Hip Ratio (WHR) 1. The proportion of one’s waist circumference to one’s hip circumference.
- 2. Chapter 6 – Managing Your Weight 2. For women a ratio of 0.8 or less and for men a ratio of 0.9 or less is considered safe. D. Measuring Body Fat 1. Ideal body fat percentages for men range from 7 to 25 percent and for women from 16 to 35 percent. 2. Methods of assessing body composition include: a. Skinfold measurement b. Home body fat analyzers c. Laboratory methods such as hydrostatic weighing and bioelectrical impedance analysis III. Understanding Weight Problems How many calories you need depends on your gender, age, body-frame size, weight, percentage of body fat, and basal metabolic rate (BMR)—the number of calories needed to sustain your body at rest. A. How Did So Many Get So Fat? 1. Consuming more calories than we burn 2. Bigger portions 3. Fast food 4. Physical inactivity 5. Passive entertainment 6. Genetics 7. Social networks 8. Marriage IV. Health Dangers of Excess Weight A. In a recent study, the first to focus on risk factors and mortality among adolescents and young adults in a national representative sample, obesity smoking, and high blood sugar levels significantly increased the risk of dying before age 55. B. The effects of obesity on health are the equivalent of 20 years of aging. C. The Impact on the Body 1. Major diseases linked to obesity include: a. Type 2 diabetes i. More than 80 percent of people with type 2 diabetes are overweight. ii. Those with BMIs of 35 or more are approximately 20 times more likely to develop diabetes. b. Heart disease and stroke
- 3. Chapter 6 – Managing Your Weight i. Overweight people are more likely to suffer from high blood pressure, high levels of triglycerides and harmful LDL cholesterol, and low levels of beneficial HDL cholesterol. ii. People with more body fat have higher blood levels of substances that cause inflammation, which may raise heart disease risk. iii. Losing 5 to 15 percent of your weight can lower your chances for developing heart disease or having a stroke. c. Cancer i. Obesity contributes to more than 100,000 cases of cancer. ii. Losing weight, researchers estimate, could prevent as many as one in every six cancer deaths. d. Other health problems i. Overweight men and women are also more likely to develop knee injuries, spinal disc degeneration, greater risk of gall stones, cognitive problems, and worsened symptoms of fibromyalgia. e. Premature death i. According to recent research, obesity is associated with at least a 20 percent increased risk of death from all causes or from heart disease. 2. The Emotional Toll a. Overweight men and women often blame themselves for becoming heavy and feel guilty and depressed as a result. V. If You’re Too Thin: How To Gain Weight A. Being underweight is not an uncommon problem, particularly among adolescent and young adult men as well as among those who diet excessively or suffer from an eating disorder. B. Suggestions for gaining weight in healthy ways: 1. If your appetite is small, eat more frequently. 2. Choose some calorie-rich foods. 3. Drink juice rather than regular or diet soda. 4. Try adding a commercial liquid meal replacement as a snack. 5. Exercise regularly. 6. Eat more of a variety of foods. VI. A Practical Guide to a Healthy Weight There are only two effective strategies for losing weight: eating less and exercising more. A. Weight Loss Diets 1. High-Protein Diets
- 4. Chapter 6 – Managing Your Weight a. The Institute of Medicine considers a range of 10 to 35 percent of calories from protein as acceptable for adults, and some diets advise even higher levels. b. Severe restriction of carbohydrates can induce ketosis, which is caused by an incomplete breakdown of fats that can lead to nausea, fatigue, and light-headedness and can worsen kidney disease and other medical problems. 2. Low-Carbohydrate, Low-Fat Diets a. Some popular diets are based on the premise that the correct proportions of various nutrients, particularly carbohydrates, fats, and proteins, lead to hormonal balance, weight loss, and greater vitality. 3. The Bottom Line a. In a recent review of weight-loss interventions, researchers identified the key components of a successful diet: i. Daily caloric intake of about 500 calories less than usual ii. Relatively high in protein iii. Moderately low in calories iv. Low glycemic index v. A minimum of 30 minutes of daily, moderate-intensity physical exercise b. Although people lose weight on any diet that helps them eat less, most dieters lose only about 5 percent of their initial weight and gain some of that back. B. Physical Activity and Exercise 1. Scientists use the acronym NEAT for nonexercise activity thermogenesis to describe “nonvolitional” movement, which may be an effective way of burning calories. 2. Although physical activity and exercise can prevent weight gain and improve health, usually it does not lead to significant weight loss. However, when combined with diet, exercise ensures that you lose fat rather than muscle and helps keep off excess pounds. 3. Moderate exercise, such as 30 to 60 minutes of daily physical activity, reduces the risk of heart disease and other health threats. 4. Exercising a minimum of 200 to 300 minutes weekly of moderately intense activity, is necessary to maintain weight loss. 5. Physical activity increases energy expenditure, builds up muscle tissue, burns off fat stores, stimulates the immune system, and possibly reprograms metabolism. C. The Psychology of Losing Weight
- 5. Chapter 6 – Managing Your Weight 1. Changing your food-related thoughts and behaviors can be the key to lasting weight loss. D. Common Diet Traps 1. Over-the-Counter Diet Pills a. An estimated 15 percent of adults—21 percent of women and 10 percent of men—have used weight loss supplements. 2. Diet Foods a. People who rely on meal replacements or snack bars often gain weight because they think that they can afford to add high-calorie treats to their diets. 3. Artificial sweeteners and fake fats a. Nutritionists caution to use artificial sweeteners and fake fats in moderation and not to substitute them for basic foods, such as grains, fruits, and vegetables. E. Maintaining Weight Loss 1. The National Weight Control Registry study the habits and lifestyles of those who’ve maintained a weight loss of at least 30 pounds for at least a year: a. Personal responsibility for change: Weight loss winners develop an internal locus of control. b. Exercise: Registry members report an hour of moderate physical activity almost every day. c. Monitoring: About 44 percent of registry members count calories, and almost all keep track of their food intake in some way. d. Vigilance: Successful losers keep tabs on their weight and size. e. Frequent eating: Those who eat frequent meals and snacks put on fewer pounds and gained fewer inches around their waists than those who ate only a couple of times each day VII. Treating Severe Obesity The number of extremely obese adults—those at least 100 pounds overweight with BMIs over 40—has quadrupled in the last two decades from 1 in 200 to about 1 in every 50 men and women. A. Prescription Drug Therapy 1. Obesity medications are meant for individuals with BMIs equal to or greater than 30 or for those with a BMI equal to or greater than 27 with at least one weight-related health problem, such as hypertension or diabetes. B. Obesity Surgery 1. Obesity, or bariatric, surgery is becoming the most popular weight loss approach for the estimated 15 million men and women who qualify as
- 6. Chapter 6 – Managing Your Weight “morbidly obese” (100 or more pounds overweight) because of their increased health risks. 2. The two most common types of procedures are: a. Gastric bypass – surgeons create an egg-sized pouch with staples and reroute food around part of the upper intestine to block absorption of calories and nutrients. b. Banding – surgeons slip an inflatable silicon band around the stomach. 3. Long-term dangers – both physical and psychological – are unknown, particularly for adolescents. VIII. Unhealthy Eating on Campus A. Introduction 1. Unhealthy eating behavior takes many forms, ranging from not eating enough to eating too much too quickly 2. Researchers have linked specific genes to some cases of anorexia nervosa and binge eating, but most believe that a variety of factors, including stress and culture, combine to cause disordered eating. B. Body Image 1. As the gap between reality and ideal grows, both genders struggle with issues related to body image, although men and women report different concerns. 2. Women compare their appearance to that of celebrities and models as well as peers more frequently than men and worry more that others will think negatively about their looks. 3. College students of different ethnic and racial backgrounds, express as much – and sometimes more – concern about their body shape and weight as whites. IX. Disordered Eating In a survey at a large, public, rural university in the mid-Atlantic states, 17 percent of the women were struggling with disordered eating. Younger women (ages 18– 21) were more likely than older students to have an eating disorder. In this study, eating disorders did not discriminate, equally affecting women of different races, religions, athletic involvement, and living arrangements. A. Extreme Dieting 1. Extreme dieters go beyond cutting back on calories or increasing physical activity. They become preoccupied with what they eat and weigh. 2. Weight loss is severe enough to cause uncomfortable physical consequences, such as weakness and sensitivity to cold.
- 7. Chapter 6 – Managing Your Weight 3. Extreme dieters may think they know a great deal about nutrition, yet many of their beliefs about food and weight are misconceptions or myths. B. Compulsive Overeating 1. People who eat compulsively cannot stop putting food in their mouths. They eat fast and eat a lot. They eat even when they are full. 2. The following behaviors may signal a potential problem with compulsive overeating: a. Turning to food when depressed or lonely, when feeling rejected, or as a reward b. A history of failed diets and anxiety when dieting c. Thinking about food throughout the day d. Eating quickly and without pleasure e. Continuing to eat even when you are no longer hungry f. Frequently talking about food, or refusing to talk about food g. Fear of not being able to stop eating once you start C. Binge Eating 1. Binge eating is the rapid consumption of an abnormally large amount of food in a relatively short time. 2. Binge eaters experience at least three of the following: a. Eating much more rapidly than usual b. Eating until they feel uncomfortably full c. Eating large amounts of food when not feeling physically hungry d. Eating large amounts of food throughout the day with no planned mealtimes e. Eating alone because they are embarrassed by how much they eat and by their eating habits 3. Binge eaters may spend up to several hours eating, and consume 2,000 or more calories worth of food in a single binge. 4. Binge eating is probably the most common eating disorder. D. Eating Disorders 1. Eating disorders affect an estimated 5 to 10 million women and 1 million men. 2. Athletes in sports involving pressure either to maintain ideal body weight or to achieve a weight that might enhance their performance are more likely to develop eating disorders. 3. Anorexia Nervosa a. Although anorexia means “loss of appetite,” most individuals with anorexia nervosa are, in fact, hungry all of the time. b. For them, food is an enemy—a threat to their sense of self, identity, and autonomy.
- 8. Chapter 6 – Managing Your Weight c. They see themselves as fat or flabby even at a normal or below-normal body weight. d. The key characteristics of anorexia nervosa include: i. Restriction of food intake, leading to a significantly low body weight for their age, health, and gender. ii. An intense fear of gaining weight or becoming fat, even though underweight. iii. Disturbance in the way individuals experience their body weight or shape. e. The incidence of anorexia nervosa has increased in the last three decades in most developed countries. f. In the restrictive type of anorexia, individuals lose weight by avoiding any fatty foods, and by dieting, fasting, and exercising. g. In the binge-eating/purging type, individuals engage in binge eating, purging, or both. 4. Bulimia Nervosa a. Individuals with bulimia nervosa go on repeated eating binges and rapidly consume large amounts of food, usually sweets, stopping only because of severe abdominal pain or sleep, or because they are interrupted. b. The characteristics include: i. Repeated binge eating ii. Repeated attempts to prevent weight gain, such as self-induced vomiting; misuse of laxatives, diuretics, or other medications; fasting; or excessive exercise iii. Binges and compensatory behaviors occur at least once a week for three months iv. Self-evaluation based on body shape and weight c. An estimated 2 percent of American women develop bulimia in adolescence or young adulthood. Key Terms anorexia nervosa binge eating binge-eating disorder body mass index (BMI) bulimia nervosa eating disorders NEAT (nonexercise activity thermogenesis) obesity overweight
- 9. Chapter 6 – Managing Your Weight waist-to-hip ratio (WHR)