The largest and longest-running comparison of diet plans found the low-carbohydrate Atkins regimen produced greater weight loss than three other popular programs -- the Zone, the Ornish and the U.S. nutritional guidelines.
The average weight reduction was small, and participants started regaining pounds by the end of the one-year study, according to the report in today's Journal of the American Medical Assn.
Still, Atkins dieters -- who consume prodigious amounts of long-demonized saturated fats but shun carbs, such as pasta and breads -- experienced significant drops in blood pressure and cholesterol.
The finding showed that even a small weight reduction can improve overall health, researchers said.
Atkins dieters lost an average of 10.4 pounds after one year, according to the report, compared with 5.7 pounds for those on a traditional balanced diet based on federal nutritional guidelines, 4.8 pounds for the high-carbohydrate Ornish diet and 3.5 pounds for the Zone diet, which calls for a set ratio of carbohydrate, protein and fat.
The study's results cast further doubt on the benefits of low-fat, high-carb diets, which have been touted for decades as the model of healthy eating.
"This study confirms the importance of reducing carbohydrates," said Dr. Frank Hu, associate professor of nutrition and epidemiology at the Harvard School of Public Health, who was not involved in the research. "Bagels, white bread, potatoes and soft drinks are the real bad guys in our diet."
The study was quickly criticized by some Atkins competitors.
Dr. Dean Ornish, president of the Preventive Medicine Research Institute in Sausalito, Calif., said the differences among the weight loss plans detected in the study were insignificant.
He added that Atkins dieters saw an increase in levels of LDL, or "bad," cholesterol.
"The conclusions of this study are highly misleading," he said.
But Atkins backers saw the study as vindication of their approach and predicted a revival of interest in the Atkins diet, whose popularity peaked five years ago but then swiftly faded.
Atkins Nutritionals Inc., which sold packaged foods based on the diet, sought bankruptcy protection in 2005. Today, the $2-billion carb-conscious food market is dwarfed by the $14.7 billion spent on low-fat products, according to AC Nielsen.
