Weight Management: Overweight, Obesity, and Underweight Chapter 9

Overweight and Obesity Major health problem in the U.S. Prevalence continues to increase Defined by BMI of 25 or greater Epidemic is worldwide

Fat Cell Development Energy in exceeds energy out Body fat Stored in fat cells of adipose tissue Body fat Number and size of fat cells Energy out exceeds energy in Fat cell size decreases; no change in number

Fat Cell Metabolism Lipoprotein lipase (LPL) activity Storage of triglycerides Obese people vs. lean people Activity in varying body regions Enzyme activity releasing and breaking down fat Fat oxidation is not efficient

Causes of Overweight & Obesity – Genetics & Epigenetics Causative role of genetics Genetic influences do seem to be involved Genetics may determine predisposition to obesity Human genome Obesity gene Codes for the protein leptin Locations of leptin secretion

Causes of Overweight & Obesity – Genetics & Epigenetics Genetic deficiency of leptin or genetic mutation Leptin resistance Roles in the body Energy regulation Others

Causes of Overweight & Obesity – Genetics & Epigenetics Adiponectin Secreted by adipose tissue Inverse correlation with body fat Benefits Ghrelin Promotes positive energy balance Inverse correlation with body weight Roles in the body beyond energy regulation

Causes of Overweight & Obesity – Genetics & Epigenetics PYY GI cells secrete in proportion to kcalories consumed Signals satiety and decreases food intake Ideal diet Maintain satiating hormones Minimize appetite stimulating hormones Low in fat and rich in fiber

Causes of Overweight & Obesity – Genetics & Epigenetics Uncoupling proteins Proteins involved in energy metabolism Two types of fat White adipose tissue Brown adipose tissue Uncoupling proteins found in both types of fat Influence basal metabolic rate (BMR)

Causes of Overweight & Obesity – Environment Encountered daily circumstances Interaction between environment and genetics Overeating Present and past eating and activity patterns influence current body weight Availability Serving sizes Physical inactivity Life requires little exertion Inactivity contributes to weight gain and poor health DRI for prevention of weight gain

Problems of Overweight and Obesity – Health Risks Three indicators BMI Waist circumference Disease risk profile Factors taken into account Beneficial weight loss Health status Motivation

Problems of Overweight and Obesity – Health Risks Overweight in good health Sometimes health is not the motivation for weight loss Obese or overweight with risk factors Two or more risk factors Obese or overweight with life-threatening condition Recommendation to lose weight

Problems of Overweight and Obesity – Perceptions & Prejudices Most obese people do not successfully lose weight and maintain the loss Social consequences Jobs, school, and in social situations Psychological problems

Problems of Overweight and Obesity – Dangerous Interventions Intervention dangers Diet books and weight-loss programs Little success with weight loss maintenance Fad diets Weight-loss products Herbal products Laws for dietary supplements Other gimmicks

Aggressive Treatments for Obesity – Drugs Strategies for weight reduction depend on: Degree of obesity Risk of disease Use drugs as part of long-term comprehensive weight-loss programs Assist with modest weight loss Drugs approved by FDA for obesity Sibutramine Orlistat Phentermine and diethylpropion Other drugs

Aggressive Treatments for Obesity – Surgery Clinically severe obesity 200,000 surgeries performed each year Reduces food capacity of stomach Effectively limits food intake Reduce production of ghrelin Health-related benefits Long-term safety and effectiveness Liposuction

Weight Loss Strategies Successful strategies Small changes Moderate losses Reasonable goals Reasonable rate of weight loss Benefits of modest weight loss Incorporation of healthy eating and physical activity

Wt Loss Strategies – Eating Plans Be realistic about energy intake Provide less energy than is needed Goal: nutritional adequacy without excess Breakfast frequency Nutritional adequacy Minimum of 1200 kcalories a day Eat small portions Eat less food at each meal; structured meal replacement plans Feel satisfied, not stuffed Lower energy density

Wt Loss Strategies – Eating Plans Remember water Assistance with weight management Focus on fiber Low in energy and high in nutrients; require effort to eat Choose fats sensibly Energy density and satiation Select carbohydrates carefully Artificial sweeteners Watch for empty kcalories Fat, sugar, and alcohol

Wt Loss Strategies – Physical Activity Best approach to weight management Moderate physical activity plus activities of daily life Combination of diet and physical activity Lose more fat Retain more muscle Regain less weight Reduction of abdominal fat

Wt Loss Strategies – Physical Activity kCalorie expenditure Body weight, intensity, and duration Greater the energy deficit, greater the fat loss Discretionary kcalorie allowance Metabolism Speeds up with activity Immediate and long-term benefits

Wt Loss Strategies – Physical Activity

Wt Loss Strategies – Physical Activity Body composition Fat decreases and lean body mass increases Strength-training exercises Appetite control Delayed appetite Inappropriate appetite Psychological benefits Self-esteem Choosing activities Spot reducing

Wt Loss Strategies – Environmental Influences Factors surrounding eating experience and the food itself Atmosphere Pleasant and comfortable equals more food Accessibility Less effort needed to obtain food, more food eaten Socializing Distractions

Wt Loss Strategies – Environmental Influences Presence Sight, smell, or thought of food can prompt eating Multiple choice Large assortments of foods increase consumption Package and portion sizes Serving containers

Weight Loss Strategies – Behavior & Attitude Behavior modification Positive, matter-of-fact attitude Become aware of behaviors Keep record Change behaviors

Weight Loss Strategies – Behavior & Attitude Cognitive skills Problem solving Cognitive restructuring Personal attitude Understand personal relationship with food Sound emotional health Support groups

Weight Loss Strategies – Weight Maintenance Successful weight loss Plateau Prevalence of successful weight loss Difficult to determine Weight loss Components of successful weight loss Changes in metabolism Takes more to prevent weight regain than to prevent weight gain

Preventing Weight Gain Preventing weight gain would benefit many people Strategies are similar to losing weight Start earlier

Public Health Programs Possibly change environment through public health law Stretch beyond individual

Underweight Affects no more than 5% of U.S. adults Weight gain is a matter of health Weight gain may be difficult Demand for energy contributes to underweight Difficult to gain weight Learn new habits and like new foods Underweight vs. anorexia nervosa

Weight-Gain Strategies Key diet planning strategies Energy-dense foods Exercise