1. © 2010 Cengage-Wadsworth Chapter 5 Weight Management Outline: 1.Overweight vs. Obesity 2.Diet Crazes 3.Eating Disorders 4.The Physiology of Weight Loss 5.Diet and Metabolism 6.Exercise: The Key to Weight Management 7.Losing Weight the Sound and Sensible Way 8.Behavior Modification & Adherence to a Weight Management Program 9.The Simple Truth

2. © 2010 Cengage-Wadsworth 1 2 3 4 5 6 7 8 9 Weight Management Obesity has become an epidemic in most developed countries around the world The WHO estimates 35% of the adult population in industrialized nations is obese The obesity level is the point at which excess body fat can lead to serious health problems

3. © 2010 Cengage-Wadsworth 1 2 3 4 5 6 7 8 9 Average weight of Americans between 1963-1965 and 1999-2002 Obesity and overweight have dramatically increased as a direct result of physical inactivity and poor dietary habits Average weight of American adults between ages 20 and 74 has increased by 25 lbs. or more since 1965

4. © 2010 Cengage-Wadsworth 1 2 3 4 5 6 7 8 9 Percentage of the adult population that is overweight (BMI ≥ 25) and obese (BMI ≥ 30) in the United States More than 66% of U.S. adults are over overweight and 32% are obese Between 1960 and 2002, the prevalence of adult obesity increased from about 13% to 30%

5. © 2010 Cengage-Wadsworth 1 2 3 4 5 6 7 8 9 Obesity trends in the United States 1985-2007 based on BMI ≥ 30 or 30 pounds overweight Rates of obesity increased in the 1990s No state reported an obesity rate above 15% before 1990 By 2007, only one state had a prevalence of less than 20% Thirty states had a prevalence ≥ 25% Three of these states had a rate above 30%

6. © 2010 Cengage-Wadsworth 1 2 3 4 5 6 7 8 9 Weight Management About 44% of all women and 29% of all men are on a diet at any given moment People spend about $40 billion yearly attempting to lose weight – over $10 billion to weight reduction centers – $30 billion to diet food sales About $100 billion spent yearly to treat obesity-related diseases

7. © 2010 Cengage-Wadsworth 1 2 3 4 5 6 7 8 9 Weight Management Excessive body weight and physical inactivity are the second leading cause of preventable death in the U.S. (over 112,000 deaths year) Obesity is more prevalent than smoking, poverty, and problem drinking Obesity and unhealthy lifestyles are the most critical public health problems of the 21st century Health risks increase at a BMI over 25 and are enhanced at a BMI over 30

8. © 2010 Cengage-Wadsworth 1 2 3 4 5 6 7 8 9 Health Consequences of Excessive Body Weight

9. © 2010 Cengage-Wadsworth 1 2 3 4 5 6 7 8 9 Overweight versus Obesity Overweight: A chronic disease characterized by a body mass index (BMI) greater than 25 but less than 30 Obesity: A chronic disease characterized by a body mass index (BMI) 30 or higher

10. © 2010 Cengage-Wadsworth 1 2 3 4 5 6 7 8 9 Tolerable Weight The media has the greatest influence on people’s perception of what constitutes ideal body weight Most people use fashion, fitness, and beauty magazines to determine what they should look like The “ideal” body shapes, physiques, and proportions seen in these magazines are rare and essentially achieved only through airbrushing and medical reconstruction

11. © 2010 Cengage-Wadsworth 1 2 3 4 5 6 7 8 9 The Weight Loss Dilemma Yo-yo dieting carries as great a health risk as being and remaining overweight Data show frequent fluctuations (up or down) in weight increase the risk of dying from cardiovascular disease Quick-fix diets should be replaced by a slow, permanent weight loss program Individuals gain the benefits of recommended body weight when they reach that weight and stay there throughout life

12. © 2010 Cengage-Wadsworth 1 2 3 4 5 6 7 8 9 The Weight Loss Dilemma Only about 10% of people who begin a traditional weight loss program without exercise lose the desired weight Only 5 in 100 keep the weight off because the body is highly resistant to permanent weight changes through calorie restrictions alone Traditional diets fail because few of them incorporate permanent behavioral changes in food selection and overall increase in physical activity and exercise

13. © 2010 Cengage-Wadsworth 1 2 3 4 5 6 7 8 9 Diet Crazes Fad diets continue to appeal to people of all shapes and sizes These diets may work for a while but their success is usually short lived Fad diets claim that dieters will lose weight by following all instructions Very low calorie diets generate a metabolic imbalance by creating a nutritional deficiency Much of the weight lost is in the form of water and protein, not fat

14. © 2010 Cengage-Wadsworth 1 2 3 4 5 6 7 8 9 Low-Carb Diets Low-carbohydrate/high-protein (LCHP) diets have been very popular – The intake of carbohydrate-rich foods--bread, potatoes, rice, pasta, cereals, crackers, juices, sodas, sweets (candy, cookies, cake), fruits and vegetables--is limited – Dieters can eat all they want of protein-rich foods including steak, ham, chicken, fish, bacon eggs, nuts, cheese, tofu, high-fat salad dressings, butter, and small amounts of a few fruits and vegetables These diets are high in fat Examples are the Atkins Diet, the Zone, Protein Power, the Carb Addict’s Diet, the South Beach Diet, Sugar Busters

15. © 2010 Cengage-Wadsworth 1 2 3 4 5 6 7 8 9 Low-carbohydrate/high-protein diets create nutritional deficiencies and contribute to the development of cardiovascular disease, cancer, and osteoporosis Without fruits, vegetables, whole grains, high-protein diets lack many vitamins, minerals, antioxidants, phytonutrients, and fiber that protect against various ailments and diseases Long-term adherence to a LCHP diet may increase one’s risk for heart disease, cancer, and osteoporosis

16. © 2010 Cengage-Wadsworth 1 2 3 4 5 6 7 8 9 Low-Carb Diets Side effects associated with LCHP diets include weakness, nausea, bad breath, constipation, irritability, lightheadedness, fatigue Your doctor should know if you go on a LCHP diet for longer than a few weeks so that your blood lipids, bone density, and kidney function can be monitored

17. © 2010 Cengage-Wadsworth 1 2 3 4 5 6 7 8 9 Low-Carb Diets Adding extra protein (10-15 grams) to a weight loss program can suppress hunger Dieters are less hungry when protein intake is increased to 30% of total calories, fat is 20%, and carbohydrates stay at 50% of total calories 10-15 grams of protein is equivalent to one and a half ounces of lean meat, two tablespoons of natural peanut butter, eight ounces of plain low-fat yogurt

18. © 2010 Cengage-Wadsworth 1 2 3 4 5 6 7 8 9 Eating Disorders Medical illnesses that involve crucial disturbances in eating behaviors thought to stem from some combination of environmental pressures Characterized by an intense fear of becoming fat even when the person is losing weight in extreme amounts Three most common types are anorexia nervosa, bulimia, and binge-eating disorder Emotional eating can also be listed as an eating disorder

19. © 2010 Cengage-Wadsworth 1 2 3 4 5 6 7 8 9 Eating Disorders People with eating disorders suffer from family and social problems The eating disorder becomes the coping mechanism to avoid dealing with these problems Controlling their body weight helps them believe they are restoring some control over their lives Eating disorders are common in industrialized nations where society encourages low-calorie diets and thinness

20. © 2010 Cengage-Wadsworth 1 2 3 4 5 6 7 8 9 Eating Disorders Most prevalent among people between the ages of 25 and 50 40% of college-age women are struggling with an eating disorder Every 1 in 10 cases occurs in men These cases often go unreported because men’s role and body image are viewed differently in our society

21. © 2010 Cengage-Wadsworth 1 2 3 4 5 6 7 8 9 Anorexia Nervosa An eating disorder characterized by self-imposed starvation to achieve and maintain very low body weight Affects 1% of the population in the U.S. Anorexics fear weight gain more than death from starvation They think of themselves as being fat even when they are emaciated because of their distorted body image They are preoccupied with food, meal planning, grocery shopping, and have unusual eating habits They will not stop the starvation They refuse to consider the behavior abnormal

22. © 2010 Cengage-Wadsworth 1 2 3 4 5 6 7 8 9 Anorexia Nervosa Physical changes from weight loss and malnutrition include: – amenorrhea (absence of menstruation) – digestive problems – sensitivity to cold – fluid and electrolyte imbalances (irregular heartbeat) – injuries to nerves and tendons – abnormalities of immune function – anemia – growth of fine body hair – dry skin – lowered skin/body temperature – hair and skin problems – mental confusion – inability to concentrate – lethargy and depression – osteoporosis

23. © 2010 Cengage-Wadsworth 1 2 3 4 5 6 7 8 9 Anorexia Nervosa Diagnostic criteria for anorexia nervosa: – Refusal to maintain body weight over a minimal normal weight for age and height – Intense fear of gaining weight even though underweight – Disturbance in perception of one’s body weight, size, or shape; undue influences of body weight or shape on self-evaluation, and denial of seriousness of current low body weight – Amenorrhea

24. © 2010 Cengage-Wadsworth 1 2 3 4 5 6 7 8 9 Anorexia Nervosa The disorder is 100% curable although it has the highest mortality rate of all psychosomatic illnesses--20% die as a result of their condition Treatment usually requires professional help Therapy is a combination of medical and psychological techniques to restore proper nutrition, prevent medical complications, and change the environment or events that triggered the disorder It can go undetected because thinness and dieting are socially acceptable

25. © 2010 Cengage-Wadsworth 1 2 3 4 5 6 7 8 9 Bulimia Nervosa An eating disorder characterized by a pattern of binge eating and purging in an attempt to lose weight and maintain low body weight More prevalent than anorexia nervosa – 1 in every 5 women on college campuses may be bulimic – More prevalent than anorexia in males Bulimics are usually healthy looking, well educated, near recommended body weight Bulimics enjoy food and often socialize around it They are emotionally insecure, rely on others, lack self- confidence and self-esteem Recommended weight and food are important to them

26. © 2010 Cengage-Wadsworth 1 2 3 4 5 6 7 8 9 Bulimia Nervosa The binge-purge cycle can be caused by stress or the compulsion to eat Bulimics periodically engage in binge eating that may last an hour or longer during which time they may eat several thousand calories – up to 10,000 calories (in extreme cases) After a short period of relief and satisfaction, feelings of deep guilt, shame, an intense fear of gaining weight emerge Purging seems to be the easiest answer

27. © 2010 Cengage-Wadsworth 1 2 3 4 5 6 7 8 9 Bulimia Nervosa Diagnostic criteria for bulimia nervosa – Recurrent episodes of binge eating characterized by eating in a discrete period of time an amount of food more than most people would eat during a similar period under similar circumstances – A sense of a lack of control over eating during the episode – Practice self-induced vomiting, fasting, excessive exercise and misuse laxatives and medications to prevent weight gain – Binge-purge cycle occurs on average at least twice a week for 3 months – Self-evaluation influenced by body shape and weight

28. © 2010 Cengage-Wadsworth 1 2 3 4 5 6 7 8 9 Bulimia Nervosa Medical problems associated with bulimia include: – cardiac arrhythmias – amenorrhea – kidney and bladder damage – ulcers – colitis – tearing of esophagus or stomach – tooth erosion, gum damage – general muscular weakness Bulimics know their behavior is abnormal and they are ashamed so they practice in secrecy A change in attitude can prevent damage or death

29. © 2010 Cengage-Wadsworth 1 2 3 4 5 6 7 8 9 Binge-Eating Disorder An eating disorder characterized by uncontrollable episodes of eating excessive amounts of food within a relatively short time Most common of the 3 main eating disorders – About 2% of U.S. adults have binge-eating disorder in any 6-month period – More common in women than in men, 3 women for every 2 men have it Depression, anger, sadness, boredom, worry can trigger an episode Bingers are usually overweight or obese as bingers do not purge

30. © 2010 Cengage-Wadsworth 1 2 3 4 5 6 7 8 9 Binge-Eating Disorder Typical symptoms include: – Eating an unusually large amount of food – Eating until uncomfortably full – Eating out of control – Eating much faster than usual during binge episodes – Eating alone due to embarrassment by how much food is consumed – Feeling disgusted, depressed, or guilty after overeating

31. © 2010 Cengage-Wadsworth 1 2 3 4 5 6 7 8 9 Emotional Eating The consumption of large quantities of food to suppress negative emotions Emotions include stress, anxiety, uncertainty, guilt, anger, pain, depression, loneliness, sadness, boredom People eat for comfort when they are at their weakest point emotionally Comfort foods often include calorie-dense, sweet, salty, and fatty foods Some foods such as chocolate help to offset negative emotions by causing the body to release mood-elevating opiates

32. © 2010 Cengage-Wadsworth 1 2 3 4 5 6 7 8 9 Emotional Eating Eating is a temporary distraction The following list of suggestions may help: – Learn to differentiate between emotional and physical hunger – Avoid storing and snacking on unhealthy foods – Keep healthy snacks handy – Use countering techniques (go for a walk instead of eating ice cream, listen to music instead of eating a candy bar) – Keep a “trigger” log and know what triggers your emotional food consumption – Work it out with exercise instead of food

33. © 2010 Cengage-Wadsworth 1 2 3 4 5 6 7 8 9 Treatment Treatment for eating disorders is available through many schools’ counseling or health center, at local hospitals, community support groups offering confidential help led by professional personnel free of charge

34. © 2010 Cengage-Wadsworth 1 2 3 4 5 6 7 8 9 Energy Balancing Equation One pound of fat is the equivalent of 3,500 calories In theory, if a person requiring 3,500 calories a day decreased intake by 500 calories per day, the person should lose 1 pound of fat in 7 days (500 x 7 = 3,500) When dieters balance caloric input against caloric output, weight loss does not always result as predicted

35. © 2010 Cengage-Wadsworth 1 2 3 4 5 6 7 8 9 Recommendation Daily caloric intakes of 1,200-1,500 calories provide the necessary nutrients if they are properly distributed over the basic food groups Weight loss should be gradual and not abrupt Under no circumstances should a person go on a diet that calls for a level of 1,200 calories or less for women or 1,500 calories or less for men

36. © 2010 Cengage-Wadsworth 1 2 3 4 5 6 7 8 9 Body composition changes as a result of frequent dieting without exercise

37. © 2010 Cengage-Wadsworth 1 2 3 4 5 6 7 8 9 Exercise: The Key to Weight Management A person that jogs 3 miles per exercise session 3 times a week burns 900 calories a week; 3,600 calories per month; 46,800 calories per year This minimal amount of exercise represents about 13.5 pounds of fat in one year Many of the health benefits that people seek by losing weight are reaped through exercise alone Exercise offers protection against premature morbidity and mortality for everyone, including people who already have risk factors for disease

38. © 2010 Cengage-Wadsworth 1 2 3 4 5 6 7 8 9 Low-Intensity vs. Vigorous-Intensity Exercise for Weight Loss A greater proportion of calories burned during low-intensity exercise are derived from fat The lower the intensity of exercise, the higher the percentage of fat used as an energy source – During low-intensity exercise, up to 50% of the calories burned may be from fat with the other 50% from glucose – With intense exercise, only 30%-40% of the caloric expenditure comes from fat Overall, twice as many calories can be burned during vigorous-intensity activity, and more fat

39. © 2010 Cengage-Wadsworth 1 2 3 4 5 6 7 8 9 Low-Intensity vs. Vigorous-Intensity Exercise for Weight Loss If you exercised for 30-40 minutes at moderate intensity and burned 200 calories, 50% (100 calories) would come from fat If you exercised at a vigorous intensity for 30-40 minutes and burned 400 calories, 120-160 calories would come from fat Whereas it is true that the percentage of fat used is greater during low-intensity exercise, the overall amount of fat used is still less during low-intensity exercise If you exercise at a low intensity, you would have to do so twice as long to burn the same number of calories Metabolic rate remains at a slightly higher level longer after vigorous-intensity exercise, so you continue to burn calories after exercise

40. © 2010 Cengage-Wadsworth 1 2 3 4 5 6 7 8 9 Comparison of Energy Expenditure between 30-40 Minutes of Low-Intensity vs. High-Intensity Exercise

41. © 2010 Cengage-Wadsworth 1 2 3 4 5 6 7 8 9 Weight Loss Myths Wearing rubberized sweat suits hastens the rate of body fluid that is lost and raises core temperature at the same time – This combination puts a person in danger of dehydration, which impairs cellular function and can cause death Mechanical vibrators like vibrating belts and turning rollers are worthless in a weight control program as fat cannot be shaken off

42. © 2010 Cengage-Wadsworth 1 2 3 4 5 6 7 8 9 Losing Weight the Sound and Sensible Way Research finds that a negative caloric balance is required to lose weight because: – People often underestimate their intake – People have trouble changing and adjusting to new eating habits – Many people take a long time to increase their activity level enough to offset the setpoint and burn enough calories to lose body fat – Most successful dieters monitor their daily caloric intake – A few people will not alter their food selection, so they must either increase physical activity, have a negative caloric balance, or both

43. © 2010 Cengage-Wadsworth 1 2 3 4 5 6 7 8 9 Caloric Expenditure of Selected Physical Activities

44. © 2010 Cengage-Wadsworth 1 2 3 4 5 6 7 8 9 Losing Weight the Sound and Sensible Way Breakfast is a critical meal while you are on a weight loss program People who skip breakfast are hungrier later in the day and end up consuming more total daily calories than those who eat breakfast Regular breakfast eaters have less of a weight problem, lose weight more effectively, and have less difficulty maintaining weight loss

45. © 2010 Cengage-Wadsworth 1 2 3 4 5 6 7 8 9 Losing Weight the Sound and Sensible Way If most of the calories are consumed during one meal, the body may slow the metabolism to store more calories in the form of fat Eating most of the calories during one meal causes a person to go hungry the rest of the day, making it difficult to stick to the diet

46. © 2010 Cengage-Wadsworth 1 2 3 4 5 6 7 8 9 Behavior Modification & Adherence to a Weight Maintenance Program Make a commitment to change Surround yourself with people who have the same weight loss goals you do as data indicate that obesity can spread through “social networks” Gender plays a role in social networks – A male’s weight has a greater effect on the weight of male friends and brothers – A woman’s weight has a greater effect on sisters and girlfriends – If you are trying to lose weight choose your friendships carefully

47. © 2010 Cengage-Wadsworth 1 2 3 4 5 6 7 8 9 The Simple Truth There is no quick and easy way to achieve and maintain excess body fat loss People have to decrease their caloric intake moderately, be physically active, and implement strategies to modify unhealthy eating behaviors Three most common reasons for relapse: – Stress-related factors – Social reasons – Self-enticing behaviors Making mistakes is human and does not mean failure