Minneapolis, Minnesota. It was here that, in 1945, thirty-six men participated in a starvation experiment conducted by Dr. Ancel Keys.

Staff prepared a brochure designed specifically to appeal to the idealism of these young men. Its cover showed three young children staring at empty bowls, above the words: "Will you starve that they be better fed?"

On February 12, 1945, Keys abruptly cut the food intake of the men from 3200 calories a day down to 1570. The starvation phase of the experiment had begun. He carefully controlled the amount they ate by serving them two meals a day prepared and weighed by the cook he had on staff. He designed the meals to be carbohydrate rich and protein poor, simulating what people in Europe might be eating, with an emphasis on potatoes, cabbage, macaroni, and whole wheat bread (all in meager amounts). Despite the reduction in food, Keys insisted the men maintain their active lifestyle, including the 22-miles of walking each week. Effects of the reduced food intake quickly became apparent. The men very soon showed a remarkable decline in strength and energy. Keys charted a 21-percent reduction in their strength, as measured by their performance on a back lift dynamometer. The men complained that they felt old and constantly tired.

Meal times became the high point of their day. They grew irritable if they weren't served their food exactly on time, or if they had to wait too long in line. Although the food was quite bland, to the men it tasted delicious. They lingered over the food, savoring every bite. Often they "souped" their meals — mixing everything with water to make it seem as if there was more.

The depth of the psychological strain experienced by the subjects astonished Keys. Although they had all seemed fully committed to the experiment before it began — Keys had screened for this specifically — cheating became a major issue as an almost uncontrollable urge to seek out food gripped them. Keys eventually imposed a "buddy system", allowing none of the men out of the lab unless they were accompanied by a chaperone.

The stress proved too much for one of the men, twenty-four-year-old Franklin Watkins. He began having vivid, disturbing dreams of cannibalism in which he was eating the flesh of an old man.

None of the men had been overweight to begin with, their average weight during the control period being only 152.7 pounds. So as they shed pounds they rapidly grew skeletally thin, their bones protruding from their skin at sharp angles. Keys carefully analyzed and recorded the other physiological changes they experienced.

From the men's point of view, the most uncomfortable change was the lack of body fat. It became difficult for them to sit down for long periods of time because their bones would grind against the seats. They also felt cold all the time.

After six months of starvation, the men had lost almost a quarter of their weight, dropping from an average of 152.7 pounds down to 115.6 pounds. And as the end of the starvation phase approached, they eagerly awaited its conclusion, fantasizing about the meals they would then be able to feast upon. Finally the last day arrived, July 28, 1945. There was an air of revelry in the lab. But the next day, July 29, proved a bitter disappointment. Although they were now in the rehabilitation phase, Keys didn't significantly increase their food levels. Instead, he divided them into four subgroups, which received 400, 800, 1200 or 1600 more calories than they had in starvation. He did this in order to investigate the optimum amount of calories for rehabilitation. But to the men — especially the men in the lowest calorie group — it seemed as if they were barely getting any more food than before. They still felt hungry all the time.

The last meal of the study was served on October 20, 1945. The men were subsequently free to depart and eat as they pleased. However, Keys convinced twelve of them to stay on at the lab for another eight weeks so he could monitor them during an "unrestricted rehabilitation" phase. Left to their own devices, Keys observed these men consume over 5000 calories a day, on average. And on occasion, some of them feasted on as many as 11,500 calories in a single day. For many months, the men reported having a sensation of hunger they couldn't satisfy, no matter how much they ate.