All of the diets were designed to be low in saturated fat and cholesterol, high in fiber, include low-glycemic carbohydrates, and reduce intake by 750 calories per day. Each participant was offered both group and individual counseling over the two years of the study.

After six months, the people in the study had lost more than nine pounds of total body fat and five pounds of lean body mass on average, but after two years had regained some of this. Comparing all four of the diet groups, there was no difference in fat loss or muscle loss. Neither did the proportion of carbohydrate, fat, or protein affect the amount of abdominal, visceral, or liver fat lost. People were able to maintain a weight loss of nearly nine pounds at the two-year mark, including a nearly three-pound loss of abdominal fat.

According to Dr. George Bray, a researcher who worked on the study, the major predictor for weight loss was adherence. The people who adhered to their assigned diet lost more weight than those who did not.

Adherence was a problem in this study. Many of the study participants did not complete the study, and the diets of those who did stick with it weren't exactly what they were supposed to be. Researchers hoped to see two of the diet groups adhere to the average-protein diet (15 percent) and the other two groups stick with the high-protein diet (25 percent). However, all four groups ate about 20 percent of their calories from protein over the two years of the study.

The take home message from this study is that any "diet" can work if total calories are consistently reduced. People will be more successful at losing weight if they choose a healthy diet plan that is easy for them to adhere to for the long haul, and they stick with it.

A breakdown of the meal plans used for the four diets in this study can be located here.

The study was published online January 18, 2012, in the American Journal of Clinical Nutrition.

Image: italianestro/Shutterstock.

This article originally appeared on TheDoctorWillSeeYouNow.com, an Atlantic partner site.

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