An imbalance between energy intake and expenditure is the primary etiology for excess weight gain. Achieving a negative energy balance by increasing physical activity and/or by restricting dietary intake is a commonly used approach to induce weight loss. These behavioral interventions, however, have resulted in a smaller than expected weight loss. The lack of success often seen in weight loss has been largely attributed to a coordinated set of compensatory mechanisms the body uses to resist an energy deficit induced by exercise or dietary restriction. This review provides a contemporary overview of these specific compensatory phenomena, the underlying mechanisms that drive them, and their practical implications for weight loss. Several sources of energy compensation have been identified including a reduction in resting metabolic rate, a reduction in non-exercise activity thermogenesis, and an increase in eating drive. However, supporting evidence for energy compensation still remains limited, and more research is needed to clarify the role various sources of energy compensation play in affecting weight loss outcomes. Given the wide range of potential compensatory responses to exercise and the interindividual variability, generic and one-size-fits-all exercise prescriptions for weight loss may not be appropriate. Based on the current literature, it appears that exercise prescription and weight control advice should not only be tailored to suit the individual and but also be holistic that consider the contribution of physiological, behavioral, and environmental constrains to energy balance regulation. |