Physical activity and weight control: conflicting findings

Purpose of review It is often hypothesized that increasing the volume of physical activity in the American lifestyle will slow and possibly even reverse the epidemic of obesity. Herein, we review the evidence pertaining to the role of physical activity in weight control from interventions performed in adults. Recent findings Evidence exists both for and against the role of physical activity in weight control. High levels of physical activity and successful maintenance of body weight may be a result of better coupling between energy intake and energy expenditure, potentially mediated by physiological changes in appetite, albeit in the presence of large interindividual variability. Prospective studies, however, find little evidence of the more physically active members of a population gaining less excess weight than those who are the least physically active. Summary When considering the impact of physical activity on body weight regulation, it is important to keep in mind that there are multiple hormones that acutely suppress (or stimulate) food intake and that the integration of these signals influence overall energy balance in a manner that is not yet fully understood. Moreover, cognitive and social influences may override these signals. Even though the impact of physical activity for weight control is still controversial, little doubt exists that increasing regular physical activity, particularly energy expended during structured exercise, is important for improving physical fitness and cardiovascular health.