Health-Enhancing Behaviors

1. Health-Enhancing Behaviors

2. Exercise

3. Types of Exercise • Aerobic Exercise • Elevated heart rate and respiration • Weight training • Resistance important for development of lean muscle mass • Increased activity • Increasing daily movement to improve fitness

4. Benefits of Exercise - Physiological • Increases in cardiovascular fitness and endurance • 30-minute/day decreases the risk of chronic disease • Improved circulation • Strengthens bones and increases joint flexibility • Improves digestion and fat metabolism • Increases muscle strength and tone • Increased longevity • by age 80, the amount of additional life attributable to aerobic exercise is between 1 and 2 years

5. Benefits of Exercise - Psychological • Psychological Effects of Exercise • Improved mood • Exercise as effective as therapy for depression for most people • Decreased anxiety • May decrease stress and protect against effect of stressors • Exercise addiction?

6. Exercise: Determinants of Regular Exercise • Exercise schedules are usually erratic • Lack of time and stress undermine good intentions • About 50% of people who initiate a voluntary exercise program are still doing it after 6 months • Individual Characteristics • Gender, weight, social support, self-efficacy predict exercise adherence • Characteristics of the Setting • Convenient and accessible settings predict adherence

7. Exercise: Characteristics of Interventions • Strategies • Stages of Change model helps understand levels of motivation • Cognitive-behavioral strategies promote adherence • Telephone and mail reminders are effective in relapse prevention • Individualized Exercise Programs • Understanding motivation and attitudes aids in development of a program of activities that are liked and are convenient

8. Diet

9. Maintaining a Healthy Diet:Overview • Controllable risk for many causes of death • 35% of U.S. population gets 5 servings of fruit and vegetables each day • Unhealthy eating contributes to 300,000+ deaths per year • Dietary change is critical for those at risk for • Coronary artery disease, hypertension • Diabetes • Cancer

10. Prevalence of Overweight and Obese Americans

11. Weight Gain/Loss Formula Wt +/- = cal absorbed through food ------------------------------------- cal spent through metab. & activity

12. Basal Metabolic Rate and Caloric Intake • Basal Metabolic Rate (BMR) • Body’s base rate of energy expenditure • Influenced by heredity, age (higher in younger people), activity level, and body composition (fat tissue has a lower metabolic rate) • Calorie • amount of energy needed to raise the temperature of 1 g of water 1 degree Celsius

13. Weight Regulation • The Search for Hunger/Satiety Signals • Feelings of hunger rise and fall with levels of glucose and insulin • Possible link to the number of fat cells in the body • Lateral Hypothalamus (LH) • Stimulation leads to hunger • Lesioning leads to self-starvation • Ventromedial Hypothalamus (VMH) • VMH lesioning leads to hunger • VMH stimulation causes an animal to stop eating

14. Short-Term Appetite Regulation • Pancreas hormone insulin helps convert glucose into fat • When glucose levels fall, insulin productions increases and we feel hungry • Cholecystokinin (CCK) — satiety hormone produced by the intestine • Ghrelin — appetite stimulant produced by stomach

15. Long-Term Weight Regulation • Laboratory mice with a defective gene for regulating the hormone leptin become obese • Leptin levels increase with body fat • Neurons in the arcuate nucleus (ARC) of the hypothalamus contain many receptors for leptin

16. Obesity: Some Basic Facts • Measuring Obesity • Body mass index (BMI) — measure of obesity calculated by dividing body weight by the square of a person’s height

17. Two Weight Extremes

18. Mortality Rates and BMI • Generally speaking, thinner people live longer; however, very thin people do not have the lowest mortality rates

19. Weight Control: Why Obesity is a Health Risk • Links with other risk factors, i.e., blood pressure • Increases risks during surgery, anesthesia administration, and childbearing • Chief cause of disability • number of people aged 30-49 who cannot care for themselves has jumped by 50% • Problems with health care • May not fit in standard wheelchairs • X-rays may not penetrate far enough • Blood pressure cuffs may not fit

20. Hazards of Obesity • Male-pattern obesity linked to atherosclerosis, hypertension, diabetes • Complications after surgery • Increased risk of several cancers • Increased mortality rates from all causes • Impact on psychological well-being • Metabolic syndrome • Weight cycling — repeated weight gains and losses through repeated dieting

21. Obesity Theories • Set-Point Hypothesis • The point at which an individual’s “weight thermostat” is supposedly set • When the body falls below this weight, an increase in hunger and a lowered metabolic rate may act to restore the lost weight • Positive Incentive Model • Food tastes good and is a powerful reinforcer for eating behavior • Social factors and other pleasurable aspects of eating are part of what is reinforcing.

22. The Biopsychosocial Model of Obesity - Biology • Heredity • Genes thought to contribute approximately 50%to the likelihood of obesity • 60% of obese people had obese biological parents • Body weights of adopted children correlate more strongly with weights of biological parents • Body weights of adopted siblings weakly correlated

23. The Biopsychosocial Model - Psychology • Stress has a direct effect on eating • Especially true for adolescents • Greater stress tied to • Eating more fatty foods • Eating less fruit and vegetables • Skipping breakfast • More between-meals snacks

24. Weight Control: Stress and Eating • 50% eat more when under stress • Women more likely to eat more under stress • Stress removes self-control in dieters/obese • Choose foods containing more water, “chewier” • Choose salty, low calorie foods • Negative emotions – sweet, high-fat foods • 50% eat less when under stress • Men, compared to women, eat less under stress • Non-dieting, non-obese suppress hunger cues

25. The Biopsychosocial Model - Social • 1975: 47% of Americans are overweight or obese • 2006: 65% are overweight or obese • More prevalent among African-Americans, Hispanic-Americans, Native Americans • Inversely related to socioeconomic status

26. The Biopsychosocial Model - Social • Cultural variation in ideal body image • African-Americans may be less preoccupied with thinness than European Americans • Acculturation of dietary customs • Japanese-American men are 3 times as likely to be obese as men living in Japan

27. Weight Control: Factors Associated with Obesity • Particular risk to “apples” rather than “pears” (fat localized in abdomen) • More psychologically reactive to stress • Greater cardiovascular reactivity • Yo-Yo dieting • Loss and regain • Affects abdominal fat

28. Weight Control: Factors Associated with Obesity • Obesity and Dieting as Risk Factors • Obesity is a risk factor for obesity • High basal insulin levels prompt overeating due to increased hunger • Obese have larger fat cells • Cycles of dieting lower metabolic rate

29. Dieting • Dieting • Successful weight loss is often defined as at least a 10% reduction of initial weight that is maintained for one year • 72% of women and 44% of men report having dieted at some point • Why Diets Fail • People are not accurate at estimating calorie needs • Dieters underestimate consumption • People find diets hard to stick with

30. Diet and Disease • Body expends only 3 calories to turn 100 calories of fat in food into body fat • Body expends 25 calories to turn 100 calories of carbohydrate into body fat • Humans have a natural craving for fat (a legacy from our evolutionary past when food was not plentiful?) • Typical Western diet: 40%–45% of total calories are from fats • Poor diet (especially saturated fat) is implicated in one-third of all cancer deaths in the United States

31. Weight Control: Treatment of Obesity • Amazon.com has 140,000 titles about dieting • Obese individuals attempt to lose weight because • It is considered unattractive (a primary reason) • It carries a social stigma (a primary reason) • They perceive that it is a health risk • It is coupled with psychological distress • Obese - often blamed for their weight • Few health practitioners advise losing weight

32. Maintaining a Healthy Diet:Interventions to Modify Diet • Individual interventions • In response to specific health risk • Education and self-monitoring are key • Cognitive-behavioral interventions • Transtheoretical Model of Change - Different interventions are required for each stage • Precontemplation • Contemplation • Preparation • Action • Maintenance

33. Weight Control: Treatment of Obesity • Dieting • Small losses, rarely maintained for long • Risk of yo-yo dieting to CHD > than risk of obesity alone • Formal investigation of low-carb diets does not suggest they are more effective than other kinds of diets • Fasting – usually employed with other techniques • Surgery – stomach stapled to reduce capacity • Appetite-Suppressing drugs • The multimodal approach • Screening, self-monitoring, control over eating, exercise • Controlling self-talk, social support, relapse prevention

34. Behavioral and Cognitive Therapy • Most behavior modification programs include the following components: • Stimulus control • Self-control • Contingency contracts • Social support • Careful self-monitoring • Cognitive behavior therapies (CBT) — focus on interdependence of feelings, thoughts, behavior, consequences, social context, and physiology

35. Weight Control: Evaluation of Cognitive-Behavioral Techniques • Efforts are somewhat successful • Losing 2 pounds/ week for 20 weeks • Maintenance for 2 years • Programs emphasize self-direction, exercise, and relapse prevention • Health psychologists suggest • Sensible eating and exercise • Rather than specific weight reduction techniques

36. Stepped Care for Obesity

37. Eating Disorders

38. Eating Disorders: Anorexia Nervosa • DSM-IV Criteria • Self-starvation • BMI chronically < 18 • Intense fear of weight gain • Disturbance of body image • Amenorrhea for at least three months

39. Health Hazards of Anorexia • Slowed thyroid function • Heart arrhythmias • Low blood pressure • Dry and yellowed skin • Anemia • Brittle bones

40. Bulimia Nervosa • DSM-IV criteria • At least two bulimic (binge-purge) episodes a week for at least 3 months • Lack of control over eating • Behavior designed to avoid weight gain • Persistent, exaggerated concern about weight

41. History and Demographics • Strong gender bias: 10 to 1 ratio of women to men • Prevalence • Anorexia nervosa: 0.5% to 1.0% of young adult and adolescent females • Bulimia nervosa: 1.0% to 3.0%

42. Biological Factors in Eating Disorders • Hypothalamic-pituitary-adrenal Axis (HPA) • HPA abnormalities that may promote depression are linked with both anorexia and bulimia • HPA abnormalities return to normal when disordered eating stops

43. Heredity and Eating Disorders? • Bulimia and identical twins (75% concordance rate) • Bulimia and fraternal twins (27% rate) • The chances that a young adult woman will be diagnosed with a clinical eating disorder are much greater if she has a female relative who has anorexia • Family history of major depression, obsessive-compulsive disorder (OCD), and anxiety

44. Psychological Factors • Competitive, semiclosed environments of some families, athletic teams, and sororities may foster disordered eating • Families of anorexics • High achieving • Competitive • Overprotective • Intense interactions • Poor conflict resolution

45. Psychological Factors • Families of bulimia patients • Above-average incidence of alcoholism, substance abuse, obesity, and depression • Anorexic and bulimic daughters rate their relationships with their parents as disengaged, unfriendly, and even hostile • Less accepted by their parents, who are perceived as overly critical, neglectful, and poor communicators

46. Sociocultural View • Dieting/disordered eating viewed as responses to social roles, cultural ideals • Shown photographs of ultra-thin actresses and models, they respond with increased shame, depression, and dissatisfaction with their own bodies

47. Body Image and the Media • Media representation of “ideal” female weight has decreased to that of the thinnest 5% to 10% of American women

48. Treatment of Eating Disorders • A range of treatments • Behavioral treatments have been used, from force-feeding to family therapy • Restoring body weight is the first priority • Drug therapy (antidepressants, appetite suppressants, opiate antagonists) is controversial

49. Cognitive Behavioral Treatments • Exposure-Response Prevention • A behavioral treatment of bulimia nervosa that attempts to prevent purging (and therefore reinforcement) following binge eating

50. How Effective Are Treatments for Eating Disorders? • Most therapies result in some short-term success, but poor long-term outcome • Cognitive behavior therapy is fairly effective as a primary prevention for binge eating in high-risk women • Some degree of disordered eating may be normative for college women; reduction of disordered eating after graduation is also normative