A comprehensive analysis by Professor Faidon Magkos from the University of Copenhagen and a German colleague reviewed available research on yo-yo dieting.
They found no strong evidence that the negative health effects often associated with weight cycling—such as increased fat mass, loss of muscle mass, reduced metabolic rate, and higher risk of type 2 diabetes and cardiovascular disease—can be attributed to yo-yo dieting itself.
The analysis also indicates that yo-yo dieting is not proven to be more harmful than persistent overweight.