© 2009 McGraw-Hill Higher Education. All rights reserved. Chapter Six: Maintaining a Healthy Weight

© 2009 McGraw-Hill Higher Education. All rights reserved. Defining Overweight and Obesity Desirable weight = weight range deemed appropriate for people, taking into consideration gender, age, and frame size Overweight = a person’s excess fat accumulation results in body weight that exceeds desirable weight by 1-19% Obesity = a person’s body weight is 20% or more above desirable weight

© 2009 McGraw-Hill Higher Education. All rights reserved. Rates of Overweight and Obesity (Adult Americans)

© 2009 McGraw-Hill Higher Education. All rights reserved.

Obesity and Disease Problems caused or complicated by obesity: Increased surgical risk Hypertension Heart disease Arthritis Stroke Type 2 diabetes Cancer Joint deterioration Fat accumulation in the abdomen (“apple” shape) is associated with greater health risks than fat accumulation in the hips (“pear” shape)

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Sociocultural Standards for Weight Body image: Subjective perception of how one’s body appears to oneself and others What is today’s Western cultural standard of the ideal body? Hourglass shape? Athletic? How does it differ by gender? Body image dissatisfaction affects self-concept More women than men are dissatisfied with their weight

© 2009 McGraw-Hill Higher Education. All rights reserved. Measuring and Assessing Weight and Body Fat Composition Body mass index (BMI) Height/weight tables Waist and hip measurement Appearance Home scale Body fat measurement Electrical impedance Bod Pod Skinfold measurements Hydrostatic weighing

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Body Mass Index (BMI) A mathematical calculation based on weight and height used to determine desirable body weight Weight (kg) ÷ [Height (m)] 2 Classification Normal: Overweight: Obese: ≥30 Extreme obesity: ≥40

© 2009 McGraw-Hill Higher Education. All rights reserved. Body Fat Measurement Young adult men Normal = 10-15% Obese = >25% Young adult women Normal = 22-25% Obese = >30%

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Body Fat Measurement Electrical impedance: Use of a harmless electrical current to calculate percent body fat Bod Pod: Measurement of air displacement to determine percent body fat Skinfold measurements: Measurement of the thickness of the fat layer just below the skin; used to calculate percent body fat Hydrostatic weighing: Weighing the body while it is submerged in water; used to calculate percent body fat

© 2009 McGraw-Hill Higher Education. All rights reserved. Causes of Obesity Calorie balance: Energy intake vs. energy output Intake = Output: Calorie balance Intake > Output: Positive calorie balance Weight gain Output > Input: Negative calorie balance Weight loss Energy needs: Basal metabolic rate (BMR) Activity requirements Thermic effect of food

© 2009 McGraw-Hill Higher Education. All rights reserved. Causes of Obesity (cont.) Genetic factors Physiological and hormonal factors Hypothyroidism Hypercellular obesity Hypertrophic obesity Metabolic factors Set point Adaptive thermogenesis

© 2009 McGraw-Hill Higher Education. All rights reserved. Causes of Obesity (cont.) Family, social, and cultural factors Environmental factors Local environment Packaging and price Unit bias Psychological factors

© 2009 McGraw-Hill Higher Education. All rights reserved.

Facts About Weight Loss

© 2009 McGraw-Hill Higher Education. All rights reserved. Weight Management Strategies: Lifestyle Approaches Balanced diet supported by portion control Moderate physical activity 60 minutes/day for weight maintenance 90 minutes/day for weight loss and maintenance Sleep Lifestyle support and problem solving

© 2009 McGraw-Hill Higher Education. All rights reserved. Weight Management Strategies: Specific Dietary Approaches Temporary calorie restriction (“dieting”) Low-calorie foods and controlled serving sizes Controlled fasting For extreme obesity Often in a hospital setting Formal or commercial weight reduction programs

© 2009 McGraw-Hill Higher Education. All rights reserved. Weight Management Strategies: Weight Loss Drugs OTC drugs and herbal supplements Ephedrine, phenylpropanolamine (now banned) Caffeine, laxatives Prescription weight loss drugs Phentermine Sibutramine Fat-blocking drugs Orlistat Prescription Xenical OTC Alli

© 2009 McGraw-Hill Higher Education. All rights reserved. Weight Management Strategies: Surgical Interventions Gastric bypass Gastric band Cosmetic Liposuction Abdominoplasty Body wrapping

© 2009 McGraw-Hill Higher Education. All rights reserved. Eating Disorders Most eating disorders involve psychological issues as well as inappropriate food choices or eating patterns Types/categories Anorexia nervosa Bulimia nervosa Binge eating disorder Chewing, spitting out food syndrome Night eating syndrome Body dysmorphic disorder Bigorexia

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Anorexia Nervosa Diagnostic criteria: Body weight 15% or more below desirable weight Fear of weight gain Distorted body image In women, absence or three of more menstrual periods In men, decreased sex hormone Serious medical complications, including death Treatment: Medical and dietary interventions, psychological treatment

© 2009 McGraw-Hill Higher Education. All rights reserved. Bulimia Nervosa Diagnostic criteria: Binge eating two or more times/week for at least 3 months Lack of control over bingeing Inappropriate compensatory behaviors (purging) Vomiting or use of laxatives, diuretics, or other medications Excessive exercise Fasting Overconcern with body image Serious medical complications Treatment: nutritional and psychological counseling, medical consultation

© 2009 McGraw-Hill Higher Education. All rights reserved. Other Eating Disorders Binge eating disorder Bingeing without compensatory purging Use food to cope; feel out of control during binge Chewing and spitting out food syndrome Night eating syndrome Body dysmorphic disorder Preoccupation with an imagined or slight flaw in one’s appearance Bigorexia Muscle dysmorphia, “Adonis complex” An obsession with getting bigger and more muscular Thinking that your body is never muscular enough

© 2009 McGraw-Hill Higher Education. All rights reserved. Chapter Six: Maintaining a Healthy Weight