Effects of weight cycling due to 'yo-yo' dieting - adapted from JAMA, October 19, 1994 - Tips from Other Journals

Health effects of weight cycling (the repeated loss and gain of weight) are controversial. Articles in the lay press and in professional publications have reported that weight cycling due to repeated attempts at weight loss ("yo-yo" dieting) may be detrimental to health. The National Task Force on the Prevention and Treatment of Obesity reviewed the evidence on weight cycling and its effects on health.

A total of 43 English-language studies of weight cycling were reviewed by experts in nutrition, obesity and epidemiology. Study design and the validity of study conclusions were evaluated.

The majority of studies did not identify an adverse effect of weight cycling on metabolism. Although observational studies have shown correlations between weight cycling and increased morbidity and mortality, most studies did not compare effects of intentional weight loss with effects of unintentional weight loss. Most study subjects were of normal weight or were only mildly obese; few studies were designed to evaluate the effect of weight cycling in obese patients.

The task force concluded that no convincing evidence shows that weight cycling has adverse effects, and that obese persons should not allow concerns about the possible hazards of weight cycling to deter them from trying to lose weight. (JAMA, October 19, 1994, vol. 272, p. 1196.)