A surprising study out of Harvard changes the way we think about dieting. When it comes to counting calories, what kind we take in may matter as how many we take in.
The Wall Street Journal reports that the research was published in the Journal of the American Medical Association and received funding from the National Institutes of Health.
USA Today reports that researchers found that “dieters who were trying to maintain their weight loss burned significantly more calories eating a low-carb diet than they did eating a low-fat diet.”
For the study, investigators “had 21 obese participants, ages 18 to 40, lose 10% to 15% of their initial body weight (about 30 pounds).”
The Los Angeles Times reports, “After that, each subject was fed three different diets for four weeks at a time: a traditional low-fat diet (60% carbohydrates, 20% fat and 20% protein), a low glycemic index diet (with 40% carbs, 40% fat and 20% protein) and a very low-carbohydrate diet a la Atkins (with 10% carbohydrates, 60% fat and 30% protein).”
Bloomberg News (6/27, Ostrow) reports that the investigators “found that those on the low-glycemic diet burned calories the equivalent of an hour of light exercise compared with those eating foods low in fat, while those on a low-carbohydrate diet burned calories equal to an hour of moderate exercise without actually engaging in physical activity … said” the study’s senior author, David Ludwig.
The New York Times “Opinionator” blog reports, however, that the low-carb diet “also had marked problems. It raised levels of CRP (c-reactive protein), which is a measure of chronic inflammation, and cortisol, a hormone that mediates stress.”
MSNBC /MyHealthNewsDaily reports that participants “on the low-fat diet experienced the most negative consequences regarding insulin resistance, lipid levels and HDL (or good) cholesterol.”
The Huffington Post reports, “Ludwig cautioned that any diet plan that drastically reduces a major class of nutrients like fat or carbs might be difficult to stick to because it is so restrictive, thereby undermining long-term maintenance of a lower weight.”
HeartWire reports that according to Ludwig, “Most of the professional nutritional associations continue to feature, expressively or implicitly, targets on fat reduction. Our work – and really many other studies – now suggest that there is absolutely no benefit by selectively targeting fat for reduction.”
HealthDay reports, “Dr. George Bray, professor of medicine at the Pennington Biomedical Research Center at Louisiana State University in Baton Rouge, expressed caution about the study conclusions.”
Bray, who co-authored an accompanying editorial, said, “There are some interesting physiological responses in this study, but translating this information for possible long-term results is difficult to do.”