Promoting Healthful Diet and Physical Activity

The year 2000 health objectives developed by the Public Health Service (U. S. Department of Health and Human Services, 1991) recognize the importance of dietary and physical activity behaviors in the maintenance of good health in adolescents (see Table 10-1). In this chapter, dietary and physical activity behaviors are discussed together, a pairing supported by both physiological and behavioral reasons. Physiologically, diet and physical activity in large part determine energy balance in the body and thus influence growth and body composition. Diet and physical activity have been found to be empirically associated in several studies (Blair, Jacobs, & Powell, 1985) and share many behavioral characteristics: they vary widely from one person to the next, they change daily within each individual, they are influenced by multiple variables, they can be performed either alone or in a social milieu and in many different settings, and they are resistant to change.