BOSTON (Reuters) – Shunning starchy foods in favor of meat and fat helps obese people shed some weight faster than a standard low-fat diet, but over time there may not be a big difference, researchers said on Wednesday.
Two studies appeared to confirm some of what the late Dr. Robert Atkins preached for decades until his death last month: that carbohydrates, a major energy source, cause weight gain.
In one six-month study, obese volunteers on the low-carbohydrate, high-fat and high-protein Atkins diet lost 13 pounds versus four pounds for obese people on a low-fat diet.
In a second year-long study, obese people on the Atkins diet lost nearly 10 pounds more after six months than volunteers on a conventional diet. But by the end of the year, the differences between the two groups were not significant, suggesting the Atkins diet is no better at helping fat people shed pounds than traditional weight-loss regimens.
“The average weight loss was greater in the low-carbohydrate groups than in the low-fat groups, but the difference was no longer significant at 12 months in the trial in which follow-up lasted that long,” said James Ware in an editorial in Thursday’s New England Journal of Medicine (news – web sites), where both studies appear.
Ware also noted that the weight lost in each study was relatively tiny compared with the volunteers’ size. The average starting weight among the volunteers in the first study was 288 pounds. Those in the second were about 50 pounds overweight.
In the United States, about 45 percent of women and 30 percent of men are on a diet. More than 60 percent of Americans are overweight and more than 30 percent are obese.
The Atkins diet, first published in 1972, has been criticized by doctors because its high fat content increases the risk of heart disease, kidney problems and cancer. The 12-month study found, however, that triglyceride levels fell further and “good” cholesterol levels rose higher on the Atkins regimen than on the low-fat diet.
The researchers in the first study, led by Frederick Samaha of the Philadelphia Veterans Affairs Medical Center, said because low-fat diets are known to reduce the risk of heart disease, longer-term studies of the Atkins diet are needed.
The authors of the second agreed, concluding: “There is not enough information to determine whether the beneficial effects of the Atkins diet outweigh its potential adverse effects on the risk of coronary heart disease in obese persons.”
“They have compared two diets, neither of which is very effective,” said diet book author Dean Ornish of the University of California at San Francisco. His own eating recommendations, which include getting just 10 percent of daily calories from fat, have been shown to reverse heart disease.