http://www.nytimes.com/2014/09/02/health/low-carb-vs-low-fat-diet.html 2014-09-15 23:36:17 A Call for a Low-Carb Diet That Embraces Fat In a finding that upends long-held notions about a healthy diet, a major study shows that avoiding carbohydrates and eating more fat contributes to weight loss and fewer cardiovascular risks. === People who avoid The findings are unlikely to be the final salvo in what has been a long and often contentious debate about what foods are best to eat for weight loss and overall health. The notion that dietary fat is harmful, particularly saturated fat, arose decades ago from comparisons of disease rates among large national populations. But more recent clinical studies in which individuals and their diets were assessed over time have produced a more complex picture. Some have provided strong evidence that people can sharply reduce their heart disease risk by eating fewer carbohydrates and more dietary fat, with the exception of trans fats. The new findings suggest that this strategy more effectively reduces body fat and also lowers overall weight. The new study was financed by the “To my knowledge, this is one of the first long-term trials that’s given these diets without calorie restrictions,” said Dariush Mozaffarian, the dean of the Friedman School of Nutrition Science and Policy at Tufts University, who was not involved in the new study. “It shows that in a free-living setting, cutting your carbs helps you lose weight without focusing on calories. And that’s really important because someone can change what they eat more easily than trying to cut down on their calories.” Diets low in carbohydrates and higher in fat and protein have been commonly used for weight loss since Dr. Robert Atkins popularized Many nutritionists and health authorities have “actively advised against” low-carbohydrate diets, said the lead author of the new study, The new study showed that was not the case. By the end of the yearlong trial, people in the low-carbohydrate group had lost about eight pounds more on average than those in the low-fat group. They had significantly greater reductions in body fat than the low-fat group, and improvements in lean muscle mass — even though neither group changed their levels of While the low-fat group did lose weight, they appeared to lose more muscle than fat. “They actually lost lean muscle mass, which is a bad thing,” Dr. Mozaffarian said. “Your balance of lean mass versus fat mass is much more important than weight. And that’s a very important finding that shows why the low-carb, high-fat group did so metabolically well.” The high-fat group followed something of a modified Atkins diet. They were told to eat mostly protein and fat, and to choose foods with primarily unsaturated fats, like fish, olive oil and nuts. But they were allowed to eat foods higher in saturated fat as well, including cheese and red meat. A typical day’s diet was not onerous: It might consist of eggs for breakfast, tuna salad for lunch, and some kind of protein for dinner — like red meat, chicken, fish, pork or tofu — along with vegetables. Low-carb participants were encouraged to cook with olive and canola oils, but butter was allowed, too. Over all, they took in a little more than 13 percent of their daily calories from saturated fat, more than double the 5 to 6 percent limit recommended by the American Heart Association. The majority of their fat intake, however, was unsaturated fats. The low-fat group included more grains, cereals and starches in their diet. They reduced their total fat intake to less than 30 percent of their daily calories, which is in line with the federal government’s dietary guidelines. The other group increased their total fat intake to more than 40 percent of daily calories. Both groups were encouraged to eat vegetables, and the low-carbohydrate group was told that eating some beans and fresh fruit was fine as well. In the end, people in the low-carbohydrate group saw markers of inflammation and Blood pressure Nonetheless, those on the low-carbohydrate diet ultimately did so well that they managed to lower their The decrease in risk on the low-carbohydrate diet “should translate into a substantial benefit,” said Dr. Allan Sniderman, a professor of cardiology at McGill University in Montreal. One important predictor of heart disease that the study did not assess, Dr. Sniderman said, was the relative size and number of LDL particles in the bloodstream. Two people can have the same overall LDL concentration, but very different levels of risk depending on whether they have a lot of small, dense LDL particles or a small number of large and fluffy particles. Eating refined carbohydrates tends to raise the overall number of LDL particles and shift them toward the small, dense variety, which contributes to Small, dense LDL is the kind typically found in heart patients and in people who have high triglycerides, central “I’ve been a strong advocate of moving saturated fat down the list of priorities in dietary recommendations for one reason: because of the increasing importance of metabolic syndrome and the role that carbohydrates play,” Dr. Krauss said. Dr. Mozaffarian said the research suggested that health authorities should pivot away from fat restrictions and encourage people to eat fewer processed foods, particularly those with refined carbohydrates. The average person may not pay much attention to the federal dietary guidelines, but their influence can be seen, for example, in school lunch programs, which is why many schools forbid whole milk but serve their students fat-free chocolate milk loaded with sugar, Dr. Mozaffarian said.