Diets with high or low protein content and glycemic index for weight-loss maintenance.

Description

The objective of this paper was to report the results of the 26-week weight-maintenance intervention phase of the Diet, Obesity, and Genes (Diogenes) study which is a pan-European, multicentre, randomized, dietary-intervention study designed to assess the efficacy of moderate-fat diets that vary in protein content and glycemic index for preventing weight regain. A total of 938 subjects entered the weight-loss phase which consisted of a low-calorie diet that provided 800 kcal/day. After this phase, 773 participants who completed the initial phase were randomly assigned to one of the five maintenance diets: a low-protein and low-glycemic-index diet, a low-protein and a high-glycemic-index diet, a high-protein and low-glycemic-index diet, a high-protein and high-glycemic-index diet, or a control diet. At the end, 548 completed the intervention. Results showed that across the different diets, participants who were assigned to the high-protein diets and to the low-glycemic-index diets were characterized by better intervention completion rate and by a higher rate of maintenance of weight loss. In addition, participants assigned to the diet that was high in protein with a low glycemic index continued to lose weight after initial weight loss. Thus, these results indicated that even a modest increase in dietary protein or a modest reduction in glycemic index values was sufficient to minimize weight regain and promote further weight loss in obese participants who had successfully lost weight previously. In their editorial comment, Ludwig DS and Ebbeling CB underlined the fact that the higher study-completion rate in the low-glycemic-index groups demonstrate the practicality of low-glycemic-index diets. The authors also discussed the recent notion suggesting that dietary composition is less important than adherence to a diet by suggesting that more studies are needed to clarify the mechanisms by which dietary composition could regulate body weight.