In 2015 the Department of Health and Human Services and the Department of Agriculture released the latest iteration of their dietary advice, Dietary Guidelines for Americans 2015-2020. Upon receiving it, Congress, citing concerns over scientific integrity, commissioned the National Academy of Medicine to review the process of generating those guidelines. In its commission, Congress asked the National Academy of Medicine for full transparency, lack of bias, and the inclusion of all latest available research, however challenging. By so asking, Congress was suggesting that the federal government’s dietary recommendations — and in particular its long-standing demonization of fats and its praise for carbohydrates — were suspect. The story starts on January 14, 1977, when the Senate Select Committee on Nutrition and Human Needs published its Dietary Goals for the United States, which, for the first time, attacked overeating. Previously, the Committee had worried about under nutrition, but by the late 1970s it worried that the epidemic of heart attacks could be attributed to an excessive intake of saturated fats. It therefore recommended that Americans eat carbohydrates instead. Unbeknownst to the vast majority of Americans, however, the theory that replacing saturated fats with carbohydrates would lower the risk of heart attacks was unproven and disputed. Moreover, the government’s dietary advice led Americans to indulge in the widespread consumption of trans unsaturated fats, which are themselves dangerous. Further, this advice coincided with — and probably contributed to — the subsequent epidemics of obesity and type 2 diabetes. Today, most nongovernmental dietary advice focuses on the benefits of plant-based fats and a Mediterranean diet, and while that, too, may be only a work in progress, it is much better than the paradigm that was disseminated by the government during the 1970s. Yet the government still propagates the oversimplified idea that fats are bad and carbohydrates are good. In fact, the federal government may be institutionally incapable of providing wise dietary advice, as Thomas Jefferson warned us in his 1787 Notes on the State of Virginia: “Was the government to prescribe to us our medicine and diet, our bodies would be in such keeping as our souls are now.”

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