Effect of Physical Activity on Food Intake: Understanding the Compensatory Response in Lean and Obese Individuals

Abstract

Background: High levels and duration of physical activity positively impact weight loss and weight maintenance. However, variability among individuals in the amount of physical activity necessary to lose or maintain weight may be influenced by a compensatory response in eating behavior. Objective: This thesis examines the effect of exercise on compensatory responses in energy intake, uniquely comparing studies conducted on lean, overweight, and obese individuals. Understanding factors influencing energy regulation is important for obesity prevention and treatment. Awareness of changes in food intake may increase compliance with physical activity recommendations and lead to better weight loss or weight stability success. Methods: Studies published from 2010-2012 were identified by comprehensive MEDLINE search and 17 articles met the inclusion criteria. Studies involved an acute exercise protocol followed by ad libitum eating. Primary outcomes measured were type, duration, intensity, and kilocalories of energy expended during physical activity, as well as energy intake following exercise. Results: 82% of studies reviewed supported a decrease or no significant change in energy intake following an exercise protocol. Among studies conducted on lean adults, only 11% found a significant increase in energy intake. However, there was a trend for greater compensation for higher intensity exercise in lean individuals. No studies conducted on overweight or obese adults supported an increase in energy intake following an exercise protocol. For both lean and overweight or obese adults, direction of energy intake response was independent of exercise duration. A majority of studies published on adults in 2012 focused on the influence of timing on the impact of exercise on subsequent food intake. These studies supported no increase in energy intake post-exercise and increasing negative percent compensation for time points closer to exercise condition. For lean adolescents study results were inconclusive, although there was a trend for no change in energy intake following exercise. However, for overweight and obese adolescents, studies supported decreases in energy intake relative to sedentary condition for high intensity exercise and no change in energy intake for moderate intensity exercise. Conclusions: Compensatory food intake responses among individuals vary according to weight and age. However, overall trends suggest a paucity of positive compensatory responses to short-term physical activity sessions. For overweight and obese adults, moderate intensity exercise does not result in over-compensatory eating behavior. This result is encouraging for obesity treatment programs aimed at promoting negative energy balance by means of moderate intensity activity. Results also endorse recommendations of high intensity exercise interventions for overweight and obese adolescents, as trends for adolescent exercise intensity support reduced intake responses to such exercise. Among lean adults and adolescents a majority of studies report no change in energy intake following exercise. However, the variability of results shows the need to individualize weight management strategies.