​Summarize Keys et al.'s experimental study with controlled starvation and its outcomes.

Conducted during World War II and reported/published in 1950, this study involved 36 young male conscientious objectors who volunteered.
1. Participants had normal weights, normal/above normal IQs, and emotional stability.
2. They ate normally for the first three months of the study to establish baseline calorie needs.
B. After the first three months, the researchers cut participant rations in half, while supplying adequate nutrients to prevent starvation; the men were almost constantly hungry. The goal was to lower their body weights by 25%.
1. Participants lost weight rapidly at first, but this did not continue.
2. They had to eat even less to keep losing weight.
3. Most of them completed the six-month project, and most met the 25% weight loss goal.
C. The researchers were surprised at the behaviors accompanying the semi-starvation diet.
1. Although initially cheerful and optimistic, the participants soon developed uncharacteristic irritable, aggressive, and combative behaviors.
2. While the hostile behavior lasted throughout the six months, the participants also developed apathy and lethargy, and avoided physical activity as much as possible.
a. They neglected their appearances, their dormitory, and their girlfriends.
3. The volunteers developed increasingly obsessive thoughts about food.
a. Meals became central to their lives.
b. They tended to be very sensitive to food's taste and to eat very slowly.
c. Around three months into the restricted diet, they were too afraid of cheating on it to leave the dormitory alone and had to go out only in groups or pairs.
d. Normal, stable, polite, dedicated young men became abnormal and unpleasant under the semi-starvation conditions of the study.
4. Participants continued their abnormal negative attitudes and food obsession during the refeeding phase of the study.
a. Refeeding had been planned as gradually increasing over three months.
b. However, the volunteers raised such strong objections that the experimenters accelerated the schedule.
c. The men then ate as often and as much as they could; some ate up to five large meals daily.
d. Most participants regained the weight they lost during the experiment by the end of the refeeding period, and some gained slightly more than they had lost.
e. Around half of the volunteers were still preoccupied with food.
f. Many of the participants had not entirely regained their pre-diet cheer and optimism.