Energy balance

Long-term calorie-restricting diets do not produce sustained weight loss or significant health improvements compared to control groups, and often result in greater weight regain than initial loss.

Relying solely on severe calorie restriction for long-term obesity management is unlikely to succeed. Most people regain the weight, often exceeding their starting weight. Health improvements seen in some studies are often due to other factors like exercise or medication reduction, not the diet itself. Sustainable weight management requires addressing the high rate of weight regain and the methodological biases that make diets appear more effective than they are.