Chapter 9 Lecture © 2014 Pearson Education, Inc. Exercise, Diet, and Weight Control

© 2014 Pearson Education, Inc. Learning Objectives Define obesity and discuss its potential causes Explain the relationship between obesity and the risk of disease Discuss the energy balance theory of weight control Explain the roles of resting and exercise metabolic rate in determining daily energy expenditure Explain the concept of optimal body weight

© 2014 Pearson Education, Inc. Learning Objectives (cont.) Outline a simple method to estimate your daily caloric expenditure List and define the four basic components of a weight-loss program Discuss several weight-loss myths Define the eating disorders anorexia nervosa, bulimia, and binge eating disorder Discuss strategies to gain body weight

© 2014 Pearson Education, Inc. What Is Optimal Body Weight? The range of optimal body fat is 8–19% for men, and 21– 32% for women Optimal body weight can be calculated using percent of body fat and body weight To compute fat-free weight (amount of total weight of bones, muscles and organs) – % total body weight – % fat weight = % fat-free weight To calculate optimal body weight (based on healthy body fat percentages) – Fat-free weight ÷ (1 – optimal % fat) = optimum weight

© 2014 Pearson Education, Inc. Factors Affecting Weight Management Genetics and Hormones Appetite control center—hypothalamus in brain –Monitors fat/sugar levels in blood and hormone receptors Physiological causes of obesity = release of hormones leptin and ghrelin Environmental Factors Eating habits, diet, and exercise Remain the primary focus Can all be controlled Energy Balance "Calories in" vs. "calories out" Resting Metabolic Rate (RMR): amount of energy expended while sedentary Exercise Metabolic Rate (EMR): amount of energy expended during exercise Complete Lab 9.1: Determining Ideal Body Weight

© 2014 Pearson Education, Inc. Energy Balance

© 2014 Pearson Education, Inc.

Designing a Weight-Loss Program Set a Realistic Goal Lose 1–2 pounds per week Aim for middle of optimal body fat range Use short-term and long-term goals Complete Lab 9.3: Weight-Loss Goals and Progress Report Assess and Modify Your Diet Keep a food diary Follow sensible dietary guidelines (no extreme or fad diets) Aim for lifelong change

© 2014 Pearson Education, Inc. Weight-Loss Program Design Plan Your Physical Activities Cardiorespiratory exercise assists fat-burning –Moderate intensity exercise 50–70% VO 2 max = optimal fat burning –Burning 250 calories and decreasing caloric intake 250 calories per day = optimal weight loss Resistance/strength training reduces muscle loss/ increases metabolic resting rate Both high-/low-intensity exercise promote weight loss Complete Lab 9.2: Estimate Caloric Expenditure/Deficit to lose 1lb of fat per week

© 2014 Pearson Education, Inc. Exercise Intensity on Fat Metabolism

© 2014 Pearson Education, Inc. Weight-Loss Program Design (cont.) Focus on Behavior Modification Make personal commitment to losing weight Develop healthy low-calorie eating habits Avoid social settings where you might overeat Exercise every day Reward yourself with non-food rewards Think positively Complete Lab 9.5: What Triggers Your Eating?

© 2014 Pearson Education, Inc. Overeating: Social and Environmental Factors

© 2014 Pearson Education, Inc. Exercise and Diet Programs to Gain Weight Increase muscle mass rather than fat mass Rigorous weight training is key to healthy weight gain Combine exercise with proper nutrition Create a positive energy balance (take in more calories than you expend) Weight Training energy and caloric expenditures ~2500 calories synthesize 1 lb of muscle –400 calories must be protein 0.25 lbs muscle can be gained per week Increase daily calories by ~90 calories

© 2014 Pearson Education, Inc. Lifetime Weight Management Weight loss and management are not short-term events Tips for lifetime weight management Cultivate a positive attitude Exercise regularly Avoid fad diets Commit to maintaining your desired body composition Prepare for occasional setbacks Get support from family and friends

© 2014 Pearson Education, Inc.

Extreme Measures for Weight Loss Some extremely obese people may need more than behavioral changes to lose weight, including Surgery - two main types –Restrictive procedures (gastric band) –Malabsorptive procedures (bypass intestine) Surgery is considered a last resort for serious cases Prescription Medications –Orlistat/Xenical –Meridia Long-term safety and effectiveness have not been established

© 2014 Pearson Education, Inc. Disordered Eating Social pressure to be thin leads to unhealthy/dangerous eating behavior Anorexia Nervosa –Severely limiting calorie intake to point of starvation –Both men and women; highest rates among adolescent girls –Starvation, excessive exercise, and laxatives Bulimia Nervosa –Cycles of binging and purging –Frequent vomiting = esophageal, tooth, and stomach damage –Sufferers may have normal weight/look "normal" Binge Eating Disorder –Binging without purging –Compulsive eating –Sufferers often gain weight Complete Lab 9.4: Assessing Body Image

© 2014 Pearson Education, Inc. Summary Weight management includes genetic, dietary, and lifestyle factors Energy balance is achieved when the calories you take in equal the calories you expend Total daily energy expenditure = resting metabolic rate + exercise metabolic rate A safe rate of weight loss is 1–2 lbs per week The four basic components of weight management are setting realistic goals, assessing and modifying dietary habits, planning physical activity, and modifying behaviors

© 2014 Pearson Education, Inc. Summary (cont.) Weight-loss goals should include both short- and long-term goals When trying to gain weight, you should gain muscle mass rather than fat Strength training and positive energy balance are needed to gain muscle mass Serious eating disorders that require professional treatment include anorexia nervosa, bulimia nervosa, and binge eating disorder