USDA Report Says High-Carb, Low-Fat Diets Most Effective
Although most diets initially can help people lose weight, "only moderate-fat, high-carbohydrate regimens" appear to "keep the pounds off for good," the Washington Post reports. A U.S. Department of Agriculture report set for release tomorrow found that any diet limiting food to about 1,500 calories per day results in short term weight loss. The report does not involve new research, but rather reviews all existing scientific literature on obesity, weight loss and diet to "evaluate the scientific soundness of various weight-loss programs." The report also determined diets' effectiveness in "trimming pounds" and maintaining weight loss and their effect on blood pressure, cholesterol, lean body mass and hunger and appetite. The Post notes that the report is "part of the government's attempt to help Americans lose weight." According to the report, the "least glitzy regimens" -- ones that recommend consuming no more than 30% of calories as fat; limiting protein consumption to about 20%; and eating more fruits, vegetables and complex carbohydrates -- are the "most nutritionally adequate" and demonstrate some of the "best improvements" in lowering cholesterol, blood fats and blood sugar, the Post reports. Diets such as those recommended by the American Heart Association and Weight Watchers fall into this category. Xavier Pi-Sunyer, director of the obesity research center at St. Luke's Roosevelt Hospital in New York, said, "Based on the scientific knowledge we have, this seems to be the most efficacious way to go and it is most likely the safest."
In addition, there is "good scientific evidence" about the Dean Ornish and Pritikin diets, which recommend very low fat and high carbohydrate intake. Such programs produce long-term weight loss, but also can be deficient in vitamin E, vitamin B12 and zinc. The least scientific evidence existed for diets recommending low-carbohydrate and high-protein intake, such as the Atkins diet. The report notes that in the short run, such diets produce greater loss of body water than fat, with the water being regained when the diet ended. However, no studies exist to support loss of body fat when the diet was followed on a long term basis or determined the diet's effect on cholesterol or blood sugar. Pi-Sunyer called the report a "good start," but added that "long-term studies that show compliance, dropout rates, sustainability, effectiveness and safety" are necessary (Squires, Washington Post, 1/10).
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