Dariush Mozaffarian, MD, of Tufts Univ. in Boston and David Ludwig, MD, of Boston Children’s Hospital, wrote the article. They said a global limit on total fat invariably lowers intake of healthful unsaturated fats from such sources as nuts, vegetable oils and fish. They said randomized trials have shown diets higher in healthful fats, when replacing carbohydrates or protein and exceeding a 35 percent dietary total fat limit, reduce the risk of cardiovascular disease.
The two doctors pointed out the Dietary Guidelines Advisory Committee report issued earlier this year neither listed total fat as a nutrient of concern nor proposed restricting its consumption. The DGAC report concluded dietary advice should emphasize optimizing types of fat and not reducing total fat.
“With these quiet statements, the DGAC report reversed nearly four decades of nutrition policy that placed priority on reducing total fat consumption throughout the population,” the JAMA article said.
The 1980 Dietary Guidelines for Americans recommended limiting dietary fat to less than 30 percent of calories. The 2005 Dietary Guidelines for Americans revised the recommendation to a range of 20 percent to 35 percent of calories.
The JAMA article said total fat recommendations should be changed in other nutritional policies as well. The Nutrition Facts Panel still uses the 30 percent limit on dietary fat although the JAMA article said that is outdated. The article said the USDA should remove the 35 percent restriction on total fat from its “Smarts Snacks in School” standards and that the Institute of Medicine should update its report on dietary reference intakes for energy and macronutrients.
“It is time for the US Department of Agriculture and Department of Health and Human Services to develop the proper signage, public health messages and other educational efforts to help people understand that limiting total fat does not produce any meaningful health benefits and that increasing healthful fats, including more than 35 percent of calories, has documented health benefits,” the article said.