The key to losing weight regardless of levels of protein, fat or carbohydrates, is eating heart-healthy, low-calorie foods and exercising, says a new study.
The research, funded by the National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health, seems to argue against blanket use of diets that do not necessarily limit calories but call for eating certain foods such as vegetables or proteins, at the expense of others.
The NIH study of 811 volunteers, 38 percent of them men and 62 percent women, aged 30-70 and either overweight or obese, looked at diets that have been popular in the United States in recent years, even as the number of obese Americans has soared.
The "Preventing Overweight Using Novel Dietary Strategies (POUNDS LOST) study found similar weight loss after six months and two years among participants assigned to four diets that differed in their proportions of these three major nutrients," said researchers.
"The diets were low or high in total fat (20 or 40 percent of calories) with average or high protein (15 or 25 percent of calories). Carbohydrate content ranged from 35 to 65 percent of calories.
"The diets all used the same calorie reduction goals and were heart-healthy low in saturated fat and cholesterol while high in dietary fibre," said researchers, whose study is published Thursday in the New England Journal of Medicine.
Participants lost an average 13 pounds (5.9 kilos) at six months and maintained a nine-pound (four-kilo) loss at two years.
"These results show that, as long as people follow a heart-healthy, reduced-calorie diet, there is more than one nutritional approach to achieving and maintaining a healthy weight," said Dr. Elizabeth Nabel, director at NHLBI.
"This provides people who need to lose weight with the flexibility to choose an approach that they're most likely to sustain: one that is most suited to their personal preferences and health needs," she stressed.
Sixty-six percent of US adults are overweight and of those, 32 percent are obese, Centers for Disease Control and Prevention data show.