In a long and well-read (over 200 comments) piece in the New York Times, two obesity researchers explain why we are fat– because we eat too much; why we eat too much–because we are always hungry; and why we are always hungry–because we eat the wrong foods. By wrong foods, they mean processed foods and high carbohydrate foods. David S. Ludwig, director of the New Balance Foundation Obesity Prevention Center at Boston Children’s Hospital and a professor of pediatrics at Harvard Medical School and Mark I. Friedman, vice president of research at the Nutrition Science Initiative don’t say anything that hasn’t been said before, but they say it persuasively, because they back it up evidence, including two studies conducted by Ludwig. In one, the Times reports, Ludwig examined 21 overweight and obese young adults after they had lost 10 to 15 percent of their body weight, on diets ranging from low fat to low carbohydrate. Despite consuming the same number of calories on each diet, subjects burned about 325 more calories per day on the low carbohydrate than on the low fat diet — amounting to the energy expended in an hour of moderately intense physical activity. In another, Ludwig found that rats fed a diet with rapidly digesting (called high “glycemic index”) carbohydrate gained 71 percent more fat than their counterparts, who ate more calories over all, though in the form of slowly digesting carbohydrate. Here’s the bottom line: “With reduced consumption of refined grains, concentrated sugar and potato products and a few other sensible lifestyle choices, our internal body weight control system should be able to do the rest. Eventually, we could bring the body weight set point back to pre-epidemic levels. Addressing the underlying biological drive to overeat may make for a far more practical and effective solution to obesity than counting calories.” Read more in the New York Times.