Chapter+9

Chapter Overview

• Focus: Energy Balance and Healthy Body Weight

• Important questions addressed:

  • Does normal body weight mean good health?

  • What factors influence overall health?

  • How to improve health and support reasonable body weight?

Learning Objectives

• Health Risks

  • Outline health risks of deficient and excessive body fat.

• Energy Balance

  • Explain concept of energy balance.

• Body Weight vs. Body Composition

  • Contrast body weight with body composition.

• Appetite Regulation

  • Identify factors affecting appetite.

• Obesity Theories

  • Summarize inside-the-body and outside-the-body theories of obesity.

• Metabolic Events

  • Describe metabolic events in energy deficit and surplus.

• Weight Management Strategies

  • Summarize measures for achieving and maintaining healthy body weight.

• Obesity Medication and Surgery

  • Describe benefits and risks of obesity medications and surgeries.

• Behavior Change Importance

  • Justify the importance of behavior change methods for weight management.

• Eating Disorders

  • Outline risk factors, symptoms, and treatments of eating disorders.

Body Fat and Health Risks

• Too Little Body Fat

  • Underweight, wasting disease.

• Too Much Body Fat

  • Overweight, obesity, and chronic diseases.

• Emphasis on body composition.

Prevalence of Body Weight Categories (U.S. Adults)

• Underweight (BMI < 18.5): 1.5%

• Obese (BMI 30–39.9): 42.4%

• Severely obese (BMI ≥ 40): 9.2%

Body Fat Distribution

• Influences obesity risks:

  • Visceral Fat: Central obesity, metabolic syndrome.

  • Subcutaneous Fat: Apple vs. pear profiles.

Evaluating Risks from Obesity

• BMI indicators:

  • 30 indicates need for treatment.

  • 25-29.9 + risk factors indicates need for treatment.

  • Waist circumference thresholds: >35 in women, >40 in men.

Discussion Topics

• Can a person with obesity be healthy?

• Are all people at a healthy body weight healthy?

• Key insights:

  • Healthy traits can exist in individuals with obesity.

  • Normal weight does not imply metabolic health.

Energy Balance Concept

• Formula: Energy in = Energy out.

• Factors affecting energy in and out: food intake, lifestyle, metabolism.

Energy Output Components

• Basal metabolism, voluntary activities, thermic effect of food.

• Modifying energy output through lean body mass and physical activity.

Body Composition vs. Body Weight

• Importance of distinguishing between weight and fat composition.

• BMI Ranges:

  • Underweight: <18.5

  • Overweight: 25-29.9

  • Obesity: ≥30

  • Limitations of BMI as a health indicator.

Measuring Body Composition

• Methods:

  • Skinfold test, waist circumference, DEXA scans.

Appetite Regulation

• Distinction between hunger and appetite.

• Factors influencing appetite: hormonal influences, stomach, brain responses.

Theories of Obesity

• Inside-the-Body: Set-point theory, genetics, microbiota influence.

• Outside-the-Body: Environmental factors, availability of food, sedentary lifestyles.

Achieving a Healthy Body Weight

• Strategies involve:

  • Healthy eating patterns, regular physical activity, behavior modification.

  • Importance of setting realistic goals.

Weight Management Techniques

• Weight Loss:

  • Appropriate calorie intake, portion awareness, meal spacing.

• Weight Gain:

  • High-energy density foods, regular meals, physical activity.

Medical Treatment of Obesity

• Options: medications, dietary supplements, obesity surgery.

• Understanding benefits and risks associated with treatments.

Eating Disorders Overview

• Types: Anorexia nervosa, bulimia nervosa, binge eating disorder.

• Importance of recognizing characteristics in athletes and addressing negative body image.