Low-Carb Beats Low-Fat for Weight Loss: Study
Still, experts agree there's no one-size-fits-all diet
By Amy Norton
MONDAY, Sept. 1, 2014 (HealthDay News) -- For people who want to lose weight and boost their heart health, cutting down on carbohydrates may work better than trimming dietary fat, a new study suggests.
In a small clinical trial of obese adults, researchers found that those assigned to follow a low-carbohydrate diet lost more weight over a year than those who followed a low-fat plan.
They also had bigger improvements in their cholesterol and triglyceride levels, the research team reports in the Sept. 2 issue of the Annals of Internal Medicine.
"On average, they lost 8 pounds more, and lost more body fat mass," said researcher Dr. Tian Hu, a doctoral fellow at Tulane University School of Public Health in New Orleans.
And while some experts have raised concerns that low-carbohydrate diets could be less than heart-healthy, these findings suggest otherwise, said Dr. Lydia Bazzano, who also worked on the study.
"Low-carb diets have traditionally been seen as potentially risky," said Bazzano, a professor of nutrition research at Tulane.
Yet in this study, people on the low-carb diet saw slightly greater improvements in their levels of "good" HDL cholesterol and triglycerides -- another type of blood fat. That could have been due to the bigger weight loss, Hu said, or to the greater amounts of "good" unsaturated fat in their diets.
But he also noted that the study ran for just one year, and it's not clear how people on either diet would fare in the long run.
There are other caveats, too, according to a dietitian who was not involved in the study.
For one, people on the low-carbohydrate diet didn't stick to it all that well. The regimen called for no more than 40 grams of carbohydrates a day -- the equivalent of about two slices of bread. But, by the end of the year, people in the low-carbohydrate group were averaging 127 grams of carbohydrates a day, noted Sonya Angelone, a spokesperson for the Academy of Nutrition and Dietetics.
"I do think that most people eat too many carbohydrates," she said. So eating fewer carbohydrates, and choosing high-quality ones -- fruits, vegetables, beans and whole grains -- is a sound idea, according to Angelone.
But one of the concerns with a low-carbohydrate diet, she said, is that people will not get enough fiber. A high-fiber diet can help ward off heart disease, and studies suggest it can aid weight loss by making people feel more full.
So instead of lowering carbohydrates "too much," Angelone said, why not replace refined carbs -- like white bread and pasta -- with fiber-rich foods?
The current study included 148 adults who were obese but free of diabetes and heart problems. About half were randomly assigned to a low-carbohydrate diet, while the rest were placed on a low-fat plan.