After working so hard to lose weight, many dieters inevitably find themselves packing on the pounds again despite their best efforts. A new study may have found the key to end this cycle of yo-yo dieting: a high protein, low glycemic index (GI) diet. The glycemic index is a scale that ranks foods based on how much they will raise your blood sugar. Low GI foods raise blood sugar slower and to a lesser degree than high GI foods.
Low GI foods include most vegetables, legumes, fruits, low-fat dairy and whole grains, while high GI foods are items like white bread, white rice, potatoes, sweetened cereals, chips and doughnuts.
A large European dietary intervention and weight maintenance study recently published in the New England Journal of Medicine tested the effectiveness of a low GI diet on maintaining weight upon completing a weight loss program.
In the study, 938 overweight individuals participated in an eight-week low calorie (800 to 1,000 calories/day) diet. Those who completed the diet and lost 8 percent or more of their body weight, 773 in total, were placed on a variety of six-month weight maintenance diets defined by protein intake and glycemic index. The control group was instructed to follow a diet with moderate protein intake. There was no caloric restriction on any of the weight maintenance diets.
In the initial eight-week low calorie diet, the participants lost an average of 24 lbs. In the maintenance phase, those assigned to a high protein, low GI diet continued to lose weight. Those participants on diets that were either high protein or low glycemic index regained less weight than those on a low protein, high GI diet. Further, those on the high protein, low GI diet had a higher rate of study completion, suggesting that the diet was more tolerable, and thus sustainable, than the other options.
The difference in glycemic index and protein intake between the diets was lower than the researchers hoped to see, yet even a modest increase in protein and decrease in glycemic index was enough to reduce weight regain.
Scientists are still debating whether a low carbohydrate, low fat, or high protein/high fat (Atkins style) diet is best for losing or maintaining weight. More people seem to lose weight with low carbohydrate diets, possibly because the higher protein level makes the diet more satisfying. This may give dieters hope that they won’t have to lose those few extra pounds ever again.