Body composition, the body’s relative amount of fat and fat-free mass, is an important component of fitness for health and wellness. People whose body composition is optimal tend to be healthier, to move more efficiently, and to feel better about themselves. They also have a lower risk of many chronic diseases. To reach wellness, you must determine what body composition is right for you and then work to achieve and maintain it.

Although people pay lip service to the idea of exercising for health, a more immediate goal for many is to look fit and healthy. Unfortunately, many people don’t succeed in their efforts to obtain a fit and healthy body because they set unrealistic goals and emphasize shortterm weight loss rather than the permanent changes in lifestyle that lead to fat loss and a healthy body composition. Successful management of body composition requires the long-term, consistent coordination of many aspects of a wellness program. However, even in the absence of changes in body composition, an active lifestyle can improve wellness (see the box “Can You Be Fit and Fat?”). This chapter focuses on defining and measuring body composition. The aspects of lifestyle that affect body composition are discussed in detail in other chapters: physical activity and exercise in Chapters 2–5 and 7, sound nutritional habits in Chapter 8, specific strategies for weight management in Chapter 9, and healthy techniques for managing stress in Chapter 10.

After reading this chapter, you should be able to Define fat-free mass, essential fat, and nonessential fat and describe their functions in the body

Explain how body composition affects overall health and wellness

Describe how body mass index, body composition, and body fat distribution are measured and assessed

Explain how to determine recommended body weight and body fat distribution