High-Protein-Low-GI Diet Helps Keep Weight Off?

As anyone, who has ever tried to lose weight knows, the Holy Grail of weight management is not losing weight – it is preventing weight regain.

Today, the New England Journal of Medicine publishes the results of a large European multicentre trial called the Diet, Obesity, and Genes (DIOGENES) Project, showing that eating slightly more protein and slightly fewer high-glycemic-index foods may make it easier to keep weight off.

The DIOGENES trial randomised 773 overweight adults from eight European countries who had lost at least 8% of their initial body weight (~11 Kg) after several weeks on an 800-kcal low-calorie diet to one of five ad libitum diets (no caloric restrictions) to prevent weight regain over a 26-week period:

1) a low-protein and low-glycemic index diet,

2) a low-protein and high-glycemic-index diet,

3) a high-protein and low-glycemic-index diet,

4) a high-protein and high-glycemic-index diet,

5) a control diet.

The interventions aimed for a difference of 15 glycemic-index units between the high-glycemic-index and low-glycemic-index diets and a difference of 12% of total energy consumed from protein between the high-protein and the low-protein diets.

While only 548 (71%) participants completed the intervention, fewer participants in the high-protein (26.4%) and the low glycemic-index (25.6%) groups dropped out than in the low-protein–high-glycemic-index group (37.4%).

Among participants who completed the study, the high-protein low-glycemic-index group was by far the most successful in keeping the weight off. The low-protein high-glycemic-index group regained the most weight.

Thus, this large, randomized study, shows that a diet moderately high in protein content and slightly reduced in glycemic index not only is a diet that people are most likely to adhere to, but also the diet with the best odds of keeping weight off (at least over the 26 week observation period).

Obviously, all diets only work for people who stay on them – the fact that only 2 in 3 participants actually completed the trial (not counting additional dropouts during the initial weight loss phase), shows how difficult it may be even for motivated volunteers to adhere to such diets.

Nevertheless, for those wondering how to keep weight off, this study may provide some clear guidance that what you eat after losing weight may be even more important than what you eat to lose weight.

Toronto, Ontario

Larsen TM, Dalskov SM, van Baak M, Jebb SA, Papadaki A, Pfeiffer AF, Martinez JA, Handjieva-Darlenska T, Kunešová M, Pihlsgård M, Stender S, Holst C, Saris WH, Astrup A, & Diet, Obesity, and Genes (Diogenes) Project (2010). Diets with high or low protein content and glycemic index for weight-loss maintenance. The New England journal of medicine, 363 (22), 2102-13 PMID: 21105792