In a three-way diet showdown, the Mediterranean diet won again, showing it may the best for losing weight and keeping it off.
A study released this week in the Journal of the American Medical Assn. compared three diets: low-fat, low-carbohydrate, and low-glycemic index. The calories in all three plans were the same, but the composition of each varied.
The low-fat diet had 60 percent of calories from carbs, 20 percent from fat and 20 percent from protein; the low-carb diet had 10 percent of calories from carbs, 60 percent from fat and 30 percent from protein, and the low-glycemic index diet had 40 percent of calories from carbs, 40 percent from fat and 20 percent from protein.
A low-glycemic index diet is akin to a Mediterranean diet, which emphasizes healthy fats such as olive oil, lean proteins and unprocessed carbohydrates such as whole grains, fruits and vegetables.
Study participants were 21 young adults who were overweight or obese. All were put on each of the diets, which were highly monitored and consisted of food prepared for them. Researchers were most interested in changes in calorie burn, hormone levels and metabolic syndrome risk factors that up the danger for heart disease, diabetes and stroke.
Total calorie burn was highest with the low-carb diet (modeled on the Atkins program), followed by the low-glycemic index diet and the low-fat diet. And although the low-carb diet also ranked most improved in metabolic syndrome factors, there was a downside: higher levels of cortisol, a hormone linked to weight gain.
The low-fat diet had some adverse effects on metabolic syndrome risk factors, and researchers noted that the small calorie burn could ultimately result in a weight re-gain. Losing weight is usually not the most difficult part of dieting—maintaining that weight loss is.
That leaves the low-glycemic diet as the overall champion, coming in with a moderate calorie burn and some metabolic improvements. “The results of our study challenge the notion that a calorie is a calorie from a metabolic perspective,” the authors wrote.
“You don’t have to go to the extreme of eliminating all carbohydrates,” study co-author Dr. David Ludwig told the Boston Globe. “By simply focusing on quality of carbohydrates we can get similar advantages to low-carbohydrate diets but without the potential downsides.”
What diet do you think is best for losing weight and keeping it off? Tell us in the comments.