There has only been one comprehensive study on the effects of starvation on human beings. An experiment by Dr. Ancel Keys, which remains the sole source of information on the subject to this day. And for good reason: it has become illegal to starve your subjects, even if they volunteer.
Brethren, Mennonites, and Quakers are all churches known for objecting to war and these were the majority of the volunteers. In 1944, brochures were sent to Civilian Public Service camps. They were giving conscientious objectors a different option than manual labor. Over 400 men volunteered, from which 36 were selected.
The experiment would be carried out in three phases: control, starvation, and recovery. In the control phase, all men moved into the same dorm room, did the same exercises (including walking 22 miles a week) and began eating exactly the same meals. Each day for 12 weeks, the men ate 3,200 calories a day. Once a baseline was found, the starvation phase began which changed only their diet (to 1,570 calories a day).
The meals given to them during this phase were based on what some Eastern Europeans were struggling to get by on (mostly carbohydrates) and subjects were still required to complete their weekly exercise. All of this took a toll on the men. They lost an average of 37.1 lbs., their strength went down by 21%, and their heart rates dropped 20 beats to conserve energy.
Two men were dismissed from the study for cheating. One man, Franklin Watkins, began to have cannibalistic dreams. It scared him into eating ice cream and milkshakes in town, and Dr. Keys found out. Watkins was initially remorseful and cried, but then turned on Dr. Keys, threatening to kill them both. Watkins was transferred to the psychiatric ward, but his was not the only case of psychological stress. In another case, a subject cut off three of his own fingers with an ax and couldn’t recall if it was intentionally.
The most common effects among them were depression, apathy and social withdrawal. Nothing they were interested in before the experiment seemed to matter anymore; whether it was political discussion or sexual interests. Most of their time was spent thinking of food and even reading cook books. This obsession with food didn’t wane in the recovery phase.
Finally, after 24-weeks, Dr. Keys increased their diets. Rehabilitation had begun, but not in the same way for everyone. Four groups were created: 1,970, 2,370, 2,770, and 3,170 calories. None of these groups felt it was enough food and after four weeks the lowest group was not making any recovery. By boosting the calories of each group by 800, Dr. Keys was able to see a marked difference. His conclusion was that a 4,000 calorie diet is needed to rehabilitate malnutrition.
“Many of the men wish to go to stricken areas to add their firsthand knowledge to the problem. So far, legal and diplomatic obstacles have thwarted previous attempts to get abroad.”
-LIFE, July 30, 1945
Though for many years some had leftover psychological effects (such as a fear of food disappearing), the men were able to fully recover physically. Dr. Keys’ full results were published at 1,385 pages long. In it, he explained that the subjects’ ability to recover showed an evolutionary connection with periods of famine. Though difficult, the human body was certainly designed to withstand a lot of torment.