In a tightly controlled dieting experiment, published in The New England Journal of Medicine obese people lost an average of just 6 to 10 pounds over two years.
The study was supposed to determine which of three types of diets works best. Instead, the results highlight the difficulty of weight loss and the fact that most diets do not work well.
More than 300 dieters were assigned to follow one of three types of diets — one with about 30 percent fat, based on American Heart Association guidelines; a Mediterranean diet; and a low-carbohydrate diet based on the Atkins diet plan.
The biggest weight loss happened in the first five months of the diet — low-fat and Mediterranean dieters lost about 10 pounds, and low-carbohydrate dieters lost 14 pounds.
By the end of two years, all the dieters had regained some, but not all, of the lost weight. The low-fat dieters showed a net loss of six pounds, and the Mediterranean and low-carbohydrate dieters both lost about 10 pounds.
Men did better on the low-carbohydrate diets, and women fared best on the Mediterranean diet..
Researchers said the results sound modest, but the small weight loss had also resulted in improvements in cholesterol and other health markers. Their conclusion -this suggests that healthy diet has beneficial effects beyond weight loss.