A low-glycemic load diet facilitates greater weight loss in overweight adults with high insulin secretion but not in overweight adults with low insulin secretion in the CALERIE Trial.

L ifestyle changes, in particular reducing energy intake, are the cornerstone of current approaches to weight loss and prevention of type 2 diabetes. However, there is currently no consensus that one dietary regimen is more effective than another for weight loss (1) or whether particular diets work better for identifiable groups of individuals. There is evidence, however, to suggest that both insulin resistance and insulin secretion play a role in body weight regulation (2– 12). Therefore, dietary factors such as the dietary glycemic load (glycemic load glycemic index [GI] available carbohydrate amount) that influence these parameters may theoretically interact with subject-specific characteristics of glucoseinsulin dynamics to influence the effect of different hypocaloric diets on weight loss or maintenance (13,14). Weight loss studies using the concept of the dietary glycemic index or glycemic load have shown conflicting results for heterogeneous groups of individuals (15–21). In a 6-month controlled feeding trial in healthy overweight adults with normal glucose tolerance, we tested the hypothesis that individuals with higher insulin secretion lose more weight when randomized to a low– glycemic load diet compared with a high– glycemic load diet.