1 Chapter 11 1 © 2012 McGraw-Hill Higher Education. All rights reserved. 2 Weight Management National Institutes of Health 68% of American adults are overweight More than 33.8% of American adults are obese In 2007-2008, 32.3% of adult men and 35.5% of adult women were obese Weight Management © 2012 McGraw-Hill Higher Education. All rights reserved. Figure 11.1 Obesity prevalence by age and sex, of American adults, 2007-2008 Weight Management 3 © 2012 McGraw-Hill Higher Education. All rights reserved. Basic Concepts of Weight Management 4 Body Composition Fat-free mass and body fat ○ Fat-free mass: bone, water, muscle, connective tissue, organ tissues, and teeth Body Fat Essential fat: necessary for body to function ○ 3-5% of total fat in men, 8-12% in women Fat Storage Adipose tissue: connective tissue in which fat is stored Subcutaneous fat: Located under the skin Visceral Fat (intra-abdominal fat): Located around major organs Factors Affecting Body Composition Genetically determined number of fat cells Cells can increase or decrease in size depending on ○ Age ○ ○ ○ ○ Sex Metabolism Diet Activity level 1 pound of fat = 3500 calories Weight Management © 2012 McGraw-Hill Higher Education. All rights reserved. 5 Energy Balance Energy balance is key to keeping a healthy ratio of fat and fat-free mass You take in energy (calories) You use up energy (calories) Energy in = energy out, you maintain your current weight Energy in > energy out, you gain weight Energy in < energy out, you lose weight Weight Management © 2012 McGraw-Hill Higher Education. All rights reserved. Figure 11.2 The energy balance equation Weight Management 6 © 2012 McGraw-Hill Higher Education. All rights reserved. Evaluating Body Weight and Body Composition 7 Overweight: Total body weight above recommended range for good health Obesity: A more serious degree of overweight Body Mass Index (BMI) Based on the concept that weight should be proportional to height Does not distinguish between fat weight and fat-free weight Weight Management © 2012 McGraw-Hill Higher Education. All rights reserved. Body Composition Analysis 8 Most accurate and direct way to determine percent body fat Hydrostatic (underwater) weighing and Bod Pod Skinfold measurements Thickness of fat under the skin Electrical impedance analysis Electricity prefers fat-free tissue Weight Management © 2012 McGraw-Hill Higher Education. All rights reserved. Figure 11.3 Body mass index (BMI) Weight Management 9 © 2012 McGraw-Hill Higher Education. All rights reserved. Excess Body Fat and Wellness 10 The health risks of excess body fat Reduces life expectancy by 10-20 years Associated with: Unhealthy cholesterol and triglyceride levels, impaired heart function, and death from cardiovascular disease Other health factors: hypertension, cancer, impaired immune function, gallbladder and kidney disease, skin problems, impotence, sleep and breathing disorders, back pain, arthritis, bone and joint disorders Strong association with diabetes mellitus: a disease that disrupts normal metabolism Weight Management © 2012 McGraw-Hill Higher Education. All rights reserved. Body Fat Distribution and Health 11 Apple shape Pear shape Assessed by measuring waist circumference Total waist measurement of more than 40 inches for men and 35 inches for women is associated with increased risk of disease Large waist circumference can be a marker for increased risk of diabetes, high blood pressure, and CVD, even in people with a BMI in the normal range Weight Management © 2012 McGraw-Hill Higher Education. All rights reserved. 12 Body Image Collective picture of the body as seen through the mind’s eye Perceptions Images Thoughts Attitudes Emotions Weight Management © 2012 McGraw-Hill Higher Education. All rights reserved. Problems Associated with Very Low Levels of Body Fat Very low body fat is less than 8-12% for women and less than 3-5% for men Extreme leanness has been linked to problems with 13 Reproductive disorders Circulatory disorders Immune system disorders Female Athlete Triad 1. 2. 3. Abnormal eating patterns Amenorrhea Decreased bone density Weight Management © 2012 McGraw-Hill Higher Education. All rights reserved. Factors Contributing To Excess Body Fat 14 Genetic Factors 25% to 40% of an individual’s body fat The tendency to develop weight is inherited, what you do does matter Physiological Factors Metabolism ○ Resting metabolic rate (RMR): the energy required to maintain vital body functions while the body is at rest Weight Management © 2012 McGraw-Hill Higher Education. All rights reserved. Lifestyle Factors 15 Eating Physical activity Psychosocial factors Emotions ○ Distraction from difficult feelings ○ Helps regulate emotions ○ Coping strategies Socioeconomic status Family and culture Weight Management © 2012 McGraw-Hill Higher Education. All rights reserved. Adopting A Healthy Lifestyle For Successful Weight Management 16 Diet and eating habits Total calories ○ MyPyramid suggestions ○ Best approach for weight loss is combining an increase of exercise with moderate calorie restriction Portion Sizes Energy (Calorie) Density Eating Habits Small, frequent meals Set rules to govern your food choices Eat in moderation Weight Management © 2012 McGraw-Hill Higher Education. All rights reserved. Physical Activity and Exercise 17 Increasing physical activity is a better approach to losing weight than cutting food intake Regular physical activity: Protects against weight gain Maintains weight loss Improves quality of life Weight Management © 2012 McGraw-Hill Higher Education. All rights reserved. Thinking and Emotions 18 Low self-esteem “Ideal self” “Self-talk” can either be selfdeprecating or motivating Realistic beliefs and goals Weight Management © 2012 McGraw-Hill Higher Education. All rights reserved. 19 Coping Strategies Appropriate coping strategies help you deal with the stresses of life and help with weight management Overeating is not an appropriate coping strategy Use food appropriately To fuel life activities Foster growth Bring pleasure Find new coping strategies Weight Management © 2012 McGraw-Hill Higher Education. All rights reserved. Approaches to Overcoming A Weight Problem Doing it 20 yourself ○ Lose 0.5-2.0 pounds per week ○ Initial weight loss occurs from fluid loss ○ Smaller, mostly fat, losses later in the diet are better than initial larger, mostly fluid, losses ○ Reasonable weight loss: 8-10% of body weight over 6 months Dietary supplements and diet aids ○ Formula drinks and food bars ○ Herbal supplements ○ Other supplements Weight Management © 2012 McGraw-Hill Higher Education. All rights reserved. 21 Weight-Loss Programs Noncommercial weight-loss programs TOPS (Take Off Pounds Sensibly) OA (Overeaters Anonymous) Commercial weight-loss programs Clinical weight-loss programs Weight Management © 2012 McGraw-Hill Higher Education. All rights reserved. 22 Prescription Drugs Appetite suppressants All prescription weight-loss drugs have potential side effects Recommended only for people who have been unable to lose weight with nondrug options or who have a BMI over 30 Weight Management © 2012 McGraw-Hill Higher Education. All rights reserved. Surgery 23 Treatment of last resort Only for severely obese 5.7% of American adults qualify as severely, or morbidly, obese NIH recommends gastric bypass for individuals with a BMI of 40 or higher Weight Management © 2012 McGraw-Hill Higher Education. All rights reserved. 24 Body Image Severe body image problems Body dysmorphic disorder (BDD) ○ Affects about 2% of Americans ○ Usually begins before age 18 Muscle dysmorphia Acceptance and change Knowing what is a healthy lifestyle change Weight Management © 2012 McGraw-Hill Higher Education. All rights reserved. 25 Eating Disorders Problems with body weight and weight control Characterized by severe disturbances in body image, eating patterns, and eatingrelated behaviors Disordered eating affects an estimated 10 million American females and 1 million males About 90% of eating disorders begin during adolescence. Some begin as young as 8 Weight Management © 2012 McGraw-Hill Higher Education. All rights reserved. 26 Anorexia Nervosa Failure to eat enough food to maintain a reasonable body weight Affects 3 million people – 95% are female Characteristics of anorexia nervosa Fear of gaining weight Distorted body image Compulsive behaviors and rituals Excessive exercise Health risks of anorexia nervosa Loss of menstruation Intolerance to cold Low blood pressure and heart rate Dry skin covered by fine body hair Hands and feet may swell and take on a blue tinge Variety of medical complications – electrolyte imbalance, heart failure, cardiac arrest Depression and suicide Weight Management © 2012 McGraw-Hill Higher Education. All rights reserved. 27 Bulimia Nervosa Recurring episodes of binge eating followed by purging Begins in adolescence or young adulthood Characteristics of bulimia nervosa ○ Rapidly consumes food, then purges ○ Done in secret ○ After a binge, individual feels ashamed, disgusted and physically and emotional drained Health risks of bulimia nervosa ○ ○ ○ ○ ○ ○ ○ ○ ○ Erodes tooth enamel Deficient calorie intake Liver and kidney damage Cardiac arrhythmia Chronic hoarseness Esophageal tearing Rupture of the stomach Increased depression Disturbances in cognitive functioning Weight Management © 2012 McGraw-Hill Higher Education. All rights reserved. 28 Other Eating Disorders Binge-Eating Similar to bulimia, except no purging behavior Likely to be obese Increased health risks Higher rates of depression and anxiety Borderline Disordered Eating Have some symptoms of eating disorders but do not meet full diagnostic criteria for eating disorder Weight Management © 2012 McGraw-Hill Higher Education. All rights reserved. Treating Eating Disorders 29 Combination of psychotherapy and medical management Individual or group therapy Address problematic eating behaviors, misuse of food, and managing emotions Anorexia Nervosa ○ Averting a medical crisis by restoring adequate body weight ○ Psychological aspects Bulimia Nervosa ○ Stabilizing eating patterns ○ Identifying and changing patterns of thinking ○ Improving coping skills Binge-Eating ○ Similar treatment protocol as bulimia nervosa Weight Management © 2012 McGraw-Hill Higher Education. All rights reserved. 30 Chapter 11 © 2012 McGraw-Hill Higher Education. All rights reserved.