Does weight cycling promote obesity and metabolic risk factors?

There remains common belief in the general community that weight cycling or ‘yo-yo dieting’ is associated with potential adverse effects on obesity and metabolic risk factors. In 1994, a review by the National Task Force on the Prevention and Treatment of Obesity concluded that weight cycling did not impact metabolism, and that weight loss attempts should not be discouraged. This study is an updated review of the literature published since 1994, to determine if weight cycling is associated with metabolic risk factors for obesity and type 2 diabetes. A systematic literature search was conducted in PubMed, ISI Web of Science and SCOPUS to identify primary studies that examined weight cycling in relation to obesity and metabolic risk factors. Thirty-one studies with human subjects were retained. Fifty-eight percent (11/19) of publications reported that a history of weight cycling was correlated with increased body fat and central adiposity. Another fifty percent (4/8) of studies reported that the presence of weight cycling increased the likelihood of future weight gain, suggesting that weight cycling is potentially problematic for individuals attempting to lose weight. The majority of studies (13/17; 76%) did not show a detrimental effect of weight cycling on risk of type 2 diabetes. There is some evidence showing that weight cycling has no effect on risk of type 2 diabetes and inconclusive evidence that a history or presence of weight cycling influences body composition, or predisposes to future obesity. The available evidence so far suggests that there is little detrimental effect of weight cycling on current and future obesity and metabolic risk, and therefore weight loss efforts in individuals with overweight/obesity should continue to be encouraged.