Khrushchev, too, looks like the kind of man his physicians must continually try to diet, and historians will some day correlate these sporadic deprivations, to which he submits “for his own good,” with his public tantrums. If there is to be a world cataclysm, it will probably be set off by skim milk, Melba toast, and mineral oil on the salad.

A.J. LIEBLING, The Earl of Louisiana, 1961

IN OCTOBER 1917, FRANCIS BENEDICT, director of the Carnegie Institution of Washington’s Nutrition Laboratory (located, as it happens, in Boston), put twelve young men on diets of roughly fourteen hundred to twenty-one hundred calories a day with the intention of lowering their body weights by 10 percent in a month. Their diets would then be adjusted as necessary to maintain their reduced weights for another two months, while Benedict and his colleagues meticulously recorded their psychological and physiological responses. A second squad of twelve men was studied as a comparison and then they were put on similar calorie-restricted diets. The results were published a year later in a seven-hundred-page report entitled Human Vitality and Efficiency Under Prolonged Restricted Diet.

Benedict hoped to establish whether humans could adjust to this lower nutritional level and thrive. His subjects lost the expected weight, but they complained constantly of hunger—“a continuous gnawing sensation in the stomach,” as described by the Carnegie report—and of being cold to the extent that several found it “almost impossible to keep warm, even with an excessive amount of clothing.” They also experienced a 30-percent decrease in metabolism. Indeed, Benedict’s subjects reduced their energy expenditure so dramatically that if they consumed more than twenty-one hundred calories a day—a third to a half less than they had been eating prior to the experiment—they would begin to regain the weight they had lost. The men also experienced significant decreases in blood pressure and pulse rate; they suffered from anemia, the inability to concentrate, and marked weakness during physical activity. They also experienced “a decrease in sexual interest and expression, which, according to some of the men, reached the point of obliteration.” That these phenomena were caused by the diet itself rather than the subsequent weight loss was demonstrated by the experience of the second squad of men, who manifested, according to the Carnegie report, “the whole picture…with striking clearness” after only a few days of dieting.