Role of physical activity in the etiology and treatment of childhood obesity.

Children in the United States are getting fatter and less active. Some childhood obesity undoubtedly develops from overeating but underactivity contributes to this condition. Various studies document less movement and lower intensity of activity in obese youth. An increase in physical activity is desirable since the health-related fitness components of flexibility, muscular and cardiovascular endurance can be improved in addition to the primary goal of body fat reduction. Evidence from animal studies suggests that exercise may alter adipose cell proliferation as well as total fat mass if initiated during growth. Regaining the natural inclination of children to be physically active may require efforts by physicians, parents, schools and special clinics. An increase in physical activity during childhood may help prevent chronic adult diseases related to inactivity and obesity.