Wednesday, the largest-ever controlled study of weight-loss methods was published in the New England Journal of Medicine, revealing that counting calories was the best method for losing the extra pounds.

The participants in the study, 800 overweight adults in Boston and Baton Rouge, Louisiana, were required to go on one of four diets that reduced calories through different combinations of fat, carbohydrates and protein, with each of the weight-loss methods cutting approximately 750 calories from their normal diets.

Nevertheless, none of the participants ate fewer than 1,200 calories per day.

The four diets were not named, still they were all based on the principles that popular plans put forward, such as the Atkins diet, which stresses the importance of low carbohydrates, Dean Ornish, which is low-fat, and the Mediterranean diet, which cuts back on animal protein.

Moreover, all the participants received group or individual counseling throughout the study.

Results showed that after two years of dieting, every diet group had lost and regained approximately the same amount of weight, irrespective of the plan they had followed.

The people involved in the study lost an average of 13 pounds six months into the program, while after the full two years, they had maintained about 9 pounds of weight loss and a two-inch decline in waist size.

Dr. Frank M. Sacks, the study’s lead author and professor of cardiovascular disease prevention at the Harvard School of Public Health, stated that people lost weight if they counted calories, regardless of the diet they chose.