One observation made repeatedly through the 1960s was that the obese favor carbohydrates, and that these constitute the great proportion of all calories they consume. Though the obese did not appear to eat more calories, on average, than the lean, they did consume more carbohydrates. Such a dietary assessment was inevitably difficult to make with any accuracy, explained Sir Derrick Dunlop of the Royal Infirmary in Edinburgh, when he reported in 1931 on the lessons he had learned from treating 523 obese patients. Nonetheless, Dunlop believed that “obesity does occur in persons without showing any direct relationship to food intake, and that a certain group of patients do become overweight on an apparently normal well-balanced diet,” and, second, “that an outstanding dietetic abnormality was an excessive intake of carbohydrate.” “In some extreme cases,” he noted, “the diet had consisted almost exclusively of sweet tea, white bread and scones.”

This observation was echoed in The Lancet in 1935 by the British physician John Anderson, and in the 1940s by Hilde Bruch, Hugo Rony, and the Harvard physician Robert Williams and his colleagues, all of whom had questioned their fat patients extensively about their diets. Their common finding was an excessive consumption of starches and sweets. Rony reported that the craving for sweets and starches among his patients was so common that it suggested an underlying physiological mechanism at work, possibly related to a greater need for or reduced availability of glucose. “It is easier to induce the gluttonous obese to control his general appetite than to control his craving for sweets,” Rony noted. One common rationale for restricting carbohydrates in weight-reducing diets was that it eliminated a disproportionately large share of the calories that the obese would normally eat.*92

When carbohydrates are restricted, however, calories may also be cut—and the reverse is nearly always true. One of the revolutionary aspects of Frank Evans’s very low-calorie diet was that it also restricted carbohydrates almost entirely.†93 When Louis Newburgh subsequently concluded that all obese patients can sustain a significant rate of weight loss for months or years if their diet is sufficiently draconian—as was the case with his patient who lost over 360 pounds—he was using Evans’s very low-calorie, very low-carbohydrate diet to generate this weight loss. His patient lost the weight while eating at most a hundred calories of carbohydrates daily. It could have been the restriction of carbohydrates that was responsible for the weight loss. It could also have been the calorie restriction.