Efficacy of very low-energy diets and meal replacements in the treatment of obesity

Background: Low-energy diets, ideally in combination with increased energy expenditure through physical activity, are the mainstay of obesity treatment. Very low-energy liquid diets (VLEDs) were developed to provide a safe alternative to starvation, with only a modest attenuation in the rate of weight loss. Aim: This paper considers the evidence concerning the efficacy of both commercial and milk-based total liquid diets, which provide a maximum of 800 kcal/day. Results: Long-term users of low-energy formula diets are a self-selected group who and these preparations acceptable. In these subjects early compliance is often good and weight losses of 8-10 kg in approximately 4-8 weeks are regularly reported. This compares favourably with acute weight losses using other treatment methods. However, there are concerns regarding the composition of tissue lost and the long-term maintenance of weight loss. Conclusion: VLEDs are a proven success in achieving significant short-term reductions in body weight. A subset of patients achieve long-term weight loss. There is evidence to suggest that meal replacements may make a contribution to the maintenance of weight loss in some individuals. Evaluation of integrated programmes using these methods for weight loss and long-term weight control is required.