Atkins was a Cornell-trained cardiologist. Between 1959 and 1963, coinciding with the early years of his practice in Manhattan, he gained fifty pounds. He eventually decided to try carbohydrate restriction, he said, “because that’s what was being taught at the time.” His attempt coincided with the 1963 publication in JAMA of a lengthy article by the University of Wisconsin endocrinologist Edgar Gordon, entitled “A New Concept in the Treatment of Obesity.” Gordon was one of the few clinicians of that era who studied fat metabolism and then designed a diet based specifically on that science. Gordon’s diet, as described in JAMA, began with a forty-eight-hour fast—“not to produce a spectacular loss of weight, but rather to break a metabolic pattern of augmented lipogenesis”*123 —and then allowed protein and fat as desired but limited carbohydrates to minimal fruits, green vegetables, and a half-slice of bread every day. “The total caloric value is quite high in terms of reducing diets,” wrote Gordon. Atkins later said his attention was caught by Gordon’s observation that his subjects lost weight without ever complaining of hunger.

In his diet, Atkins replaced the two-day initiatory fast with a week or more of complete carbohydrate restriction, under the assumption, as the Atlanta physician Walter Bloom had noted, that the two states were physiologically identical. Atkins said he lost twenty-eight pounds in a month and felt energized in the process. In 1964, while Atkins was personally reaping the benefits of his diet, he was also working part-time as a company physician with AT&T. The junior executives noticed his weight loss, so he told them about the diet. Sixty-five of them eventually tried it, as Atkins told it, and all but one reduced to their desired weight. The sole exception wanted to lose eighty pounds but lost only fifty.

Atkins then started treating obese patients out of his cardiology clinic and developed the diet as he came to prescribe it in his book. He instructed his patients to start off with an initiation period, eating no carbohydrates other than a small green salad twice a day. Once they were losing weight at a suitably rapid rate, they could begin adding small amounts of carbohydrates back into their diet until they reached what he called the critical carbohydrate level, when their weight loss either leveled off or could no longer be maintained. Then they would have to back off again on the carbohydrates to experience further benefit from the diet. He also had them check their urine for ketone bodies—with the same ketosticks used commonly by diabetics—to ensure that they remained in ketosis and were still burning body fat. The reliance on ketosis to initiate and maintain weight loss, and the progressive addition of carbohydrates to the diet, are what Atkins considered his contributions to the clinical science of carbohydrate restriction.*124 His career as a diet doctor grew slowly until 1966, when the women’s fashion magazines began recommending his diet, and his business boomed. After Vogue popularized the diet in 1970, Atkins set out to write Diet Revolution, which was then advertised as “the famous Vogue superdiet explained in full.”