Is weight cycling detrimental to health? A review of the literature in humans.

Weight cycling has been hypothesized to have deleterious metabolic, behavioral and health consequences. The majority of clinical studies in humans do however not support the hypothesis that weight cycling per se influences the amount of velocity of subsequent weight loss. Both natural and experimental weight cycling studies have failed to demonstrate permanent alterations of body composition or body fat distribution. Studies found little evidence that weight cycling affects resting energy expenditure. Further research on postulated effects of weight cycling on other components of energy expenditure is needed. A history of weight cycling is not related to alterations in fat mobilization or in cardiovascular risk factors such as blood pressure and serum lipids, but weight variability may be associated with decreases in glucose tolerance over time. The potential impact of weight cycling on dietary preference for fat, on psychological adjustment or on disordered eating behavior, including binge eating, deserves further investigation. The data from large epidemiological databases suggesting a link between body weight fluctuation and excess mortality are sufficiently provocative to encourage further research into the association, but do not override the potential benefits of weight loss in obese patients.