Chapter 1. Body Composition: What Are We Made of? -- Chapter 2. Variation in Body Size and Obesity -- Chapter 3. Genetics and Obesity -- Chapter 4. Non-dietary Factors and Weight Gain -- Chapter 5. Diet and Obesity -- Chapter 6. Obesity and Disease -- Chapter 7. Dieting, Physical Activity and Weight Loss -- Chapter 8. Drugs and Weight Loss -- Chapter 9. Surgery and Weight Loss -- Chapter 10. Alternative Weight Loss Methods.