The role of physical activity in the prevention and management of obesity.

The United States is facing 2 major lifestyle-related epidemics that are intricately linked: an epidemic of obesity and an epidemic of inactivity. Multiple interactions exist between lack of physical activity and obesity. Increased physical activity lowers the risk of obesity, may favorably influence distribution of body weight, and confers a variety of health-related benefits even in the absence of weight loss. Physical activity is important for achieving proper energy balance, which is needed to prevent or reverse obesity. Not only is energy expended during physical activity, physical activity also has a positive effect on resting metabolic rate. Regular physical activity can improve body composition. Properly designed programs of physical activity may preserve or even increase lean muscle mass during weight loss. Physical activity has also been strongly associated with maintenance of weight loss. Physical activity that expends 1,500 to 2,000 kcal/week appears necessary to maintain weight loss. Numerous studies have shown that the combination of proper nutrition and regular physical activity is the most effective intervention for weight loss and maintenance of weight loss. Walking is the most convenient and logical way most obese persons can increase their physical activity. Physical activity plays multiple roles in the prevention and treatment of obesity. Dietitians and other health care workers who treat obese patients should understand the role physical activity plays in comprehensive obesity treatment as well as how to incorporate a physical activity prescription in treatment plans for obese clients.