Earlier this month, in the battle for public opinion over which diet is best, low-carb or low-fat, the latter suffered a major defeat. A recent study out of Tulane University found that law-carb diets are better for losing weight and protecting against heart disease, setting the blogosphere afire with this latest news.
The study, whose results were published in the Annals of Internal Medicine, followed 148 obese patients who were randomly assigned either a low-carb diet (40 grams of digestible carbs a day) or low-fat (30 percent of daily calories from fat) for a year. The dieters were given no strict calorie or exercise guidelines.
After a year, the low-carb group lost an average of 7.7 pounds more than the low-fat group. The blood levels of certain fats that are predictors of heart disease risk also improved more in the low-carb group. While low-density lipoprotein cholesterol for both groups were about the same, the low-carb group saw a spike in so-called “good” HDL cholesterol and a decline in the ratio of bad to good cholesterol.
Dr. Lydia Bazzano, lead author, said the study was significant because it challenged the perception that low-fat diets are better for preventing heart disease. “Over the years, the message has always been to go low-fat,” Bazzano said. “Yet we found those on a low-carb diet had significantly greater decreases in estimated 10-year risk for heart disease after 6 and 12 months than the low-fat group.”
So does this mean you can start eating ribs round the clock? Not exactly.
In my opinion, what the report illuminated was how a cursory review of a study by the media can lead to confusion among the masses—especially among those of us overwhelmed by the constant stream of information concerning how to lose weight and eat healthier.
On closer inspection, the results appeared more common sense than ground-breaking. For starters, in the low-carb group, 41 percent of the fat participants consumed came from healthy monosaturated fats and polyunsaturated fats (e.g. olive oil) and only 13 percent came from saturated fat. So no binging on cheesesteaks and burgers (without the bread), but maybe allow for previously taboo walnuts and/or avocados.
Understanding the guidelines that the low-fat dieters were prescribed during the course of the study is equally important. Neal Barnard, M.D. president of Physicians Committee for Responsible Medicine, wrote in a HuffPo article under the low-fat diet:
Someone following this definition could consume a McDonald’s fruit-and-yogurt parfait with granola and a strawberry banana smoothie for breakfast, a grilled-chicken ranch BLT sandwich and a large Coke for lunch, and a double cheeseburger with a large Coke for dinner. In fact, one could consume nearly double the total amount of fat in all of these foods and still stay within what this study calls a “low-fat” diet.
So what does all of this mean for the Jane dieter trying to lose weight, eat healthy, and prevent heart disease? I think Frank Hu, a nutrition researcher from Harvard School of Public Health said it best in a USA Today article:
“It’s possible to have a healthy low-fat diet, one rich in fruits, vegetables, nuts, legumes, and whole grains, but not loaded with sugar and white bread, and also possible to have a healthy low-carb diet, one not loaded with bacon and sausage,” he said. “What matters most is that the individual can stick to the diet over the long term”