ABSTRACT
There is considerable interest in the role of physical activity (PA) in the prevention and treatment of obesity. Do low levels of PA increase the risk of obesity? Can increases in PA help in the prevention or treatment of obesity? While total physical activity appears to have declined over the last several decades, the average amount of leisure time physical activity (LTPA) appears to have remained relatively constant. However, total leisure time has increased, with the extra time spent in sedentary activities for most people. Although LTPA is a small part of total energy expenditure, there is evidence that the risk of obesity is increased when LTPA is low. Because it is under voluntary control, LTPA is a target for interventions to increase PA in order to prevent the development of obesity and to prevent weight regain after weight loss. This chapter will focus on how PA performed during leisure time, which primarily reflects an individual’s choice to engage in exercise, is related to obesity.
