The myth of the yo-yo: consistent rate of weight loss with successive dieting by VLCD.

Four subjects in a recent trial of eight weeks dieting with the 405 kcal/day, 42 g protein formula (Cambridge diet extra), had participated 18 months previously in an 8-week trial using the 330 kcal/day Cambridge diet formula. This permitted a quantitative comparison of two similar dieting episodes, but following substantial weight loss and variable weight regain after a successful experience with a very low calorie diet. Within the reasonable bounds of comparison between outpatient dieting experiences, there was no suggestion of impairment in ability to lose weight in subsequent dieting after weight loss on a VLCD. The experience of these subjects would not support the contention that lasting metabolic debilitation had occurred that could be attributed to repeated dieting experiences with VLCD.