But by that time there had been a sea change. Now even Brody herself was recommending a diet rich in potatoes, rice, and spaghetti for the same purpose. “We need to eat more carbohydrates,” Brody declared. “Not only is eating pasta at the height of fashion…. It can help you lose weight.” The carbohydrate had become heart-healthy diet food. Now it was the butter rather than the bread, the sour cream on the baked potato that put on the pounds. The bread and the potato themselves were no longer the cause of weight gain but the cure. When a committee of British authorities compiled their “Proposals for Nutritional Guidelines for Health Education in Britain” in 1983, they had to explain that “the previous nutritional advice in the UK to limit the intake of all carbohydrates as a means of weight control now runs counter to current thinking….”

This was one of the more remarkable conceptual shifts in the history of public health. As clinical investigators were demonstrating the singular ability of carbohydrate-restricted diets to generate significant weight loss without hunger,*3 the mainstream medical establishment was insisting, as in a 1973 editorial by the American Medical Association, that the diets were dangerous fads—“bizarre concepts of nutrition and dieting [that] should not be promoted to the public as if they were established scientific principles.”

Just four months after the AMA publicly censured the use of these diets in The Journal of the American Medical Association, obesity researchers from around the world gathered in Bethesda, Maryland, for the first conference on obesity ever hosted by the National Institutes of Health. The only talk on the dietary treatment of obesity was presented by Charlotte Young, a well-known dietitian and nutritionist at Cornell University who had been studying and treating obesity for twenty years. Young first discussed the work of Margaret Ohlson, chair of nutrition at Michigan State University, who had tested carbohydrate-restricted diets in the early 1950s. “The diets developed by Ohlson,” reported Young, “gave excellent clinical results as measured by freedom from hunger, allaying of excessive fatigue, satisfactory weight loss, suitability for long term weight reduction and subsequent weight control.” She then presented the results of her research at Cornell, testing Banting-like diets on overweight young men. As in the other reports over the last century, she noted, her subjects seemed to lose weight by restricting only sugars and starches, without feeling any particular sense of hunger. Moreover, the less carbohydrates in their diets, the greater their weight loss, even though all her subjects were eating equivalent amounts of calories and protein. “No adequate explanation could be given,” Young reported, implying that further scientific research might be important to clarify this issue.