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Chapter Six: Maintaining a Healthy Weight. Defining Overweight and Obesity. Desirable weight = weight range deemed appropriate for people, taking into consideration gender, age, and frame size
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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
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)
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
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
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: 18.5-24.9 • Overweight: 25.0-29.9 • Obese: ≥30 • Extreme obesity: ≥40
Other Methods used to Assess Weight • Height/ Weight Tables • Used to determine ideal weight based on gender, height, and frame size • Waist and Hip Measurement • Correlation between the amount of fat in the abdominal cavity and serious health risks • Appearance • Home Scale
Body Fat Measurement • Young adult men • Normal = 10-15% • Obese = >25% • Young adult women • Normal = 22-25% • Obese = >30%
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
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
Causes of Obesity (cont.) • Genetic factors • Physiological and hormonal factors • Hypothyroidism • Hypercellular obesity • Hypertrophic obesity • Metabolic factors • Set point • Adaptive thermogenesis
Causes of Obesity (cont.) • Family, social, and cultural factors • Environmental factors • Local environment • Packaging and price • Unit bias • Psychological factors
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
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
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
Weight Management Strategies: Surgical Interventions • Gastric bypass • Gastric sleeve • Gastric band • Vertical banded • Laproscopic adjustable • Cosmetic • Liposuction • Abdominoplasty • Body wrapping • Lipodissolve
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
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
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
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