Low-fat, low-carb or high-protein? The kind of diet doesn’t matter, scientists say. All that really counts is cutting calories and sticking with it, according to a federal study that followed people for two years.
However, participants had trouble staying with a single approach that long and the weight loss was modest for most.
As the world grapples with rising obesity, millions have turned to popular diets like Atkins, Zone and Ornish that tout the benefits of one nutrient over another.
Some previous studies have found that low carbohydrate diets like Atkins work better than a traditional low-fat diet. But the new research found that the key to losing weight boiled down to a basic rule — calories in, calories out.
“The hidden secret is it doesn’t matter if you focus on low-fat or low-carb,” said Dr. Elizabeth Nabel, director of the National Heart, Lung and Blood Institute, which funded the research.
Limiting the calories you consume and burning off more calories with exercise is key, she said.
The study, which appears in Thursday’s New England Journal of Medicine, was led by Harvard School of Public Health and Pennington Biomedical Research Center in Louisiana.
The study compared high quality, heart healthy diets and “not the gimmicky popular versions,” said Katz, who had no role in the study. Some popular low-carb diets tend to be low in fiber and have a relatively high intake of saturated fat, he said.
Other experts were bothered that the dieters couldn’t keep the weight off even with close monitoring and a support system.
“Even these highly motivated, intelligent participants who were coached by expert professionals could not achieve the weight losses needed to reverse the obesity epidemic,” Martijn Katan of Amsterdam’s Free University wrote in an accompanying editorial.