 Minnesota Starvation Experiment : To study the effects of diet and nutrition , Dr. Ancel Keys of the University of Minnesota Laboratory of Physiological Hygiene placed 32 conscientious objectors on a controlled diet . For three months they were given a normal 3 @,@ 200 calories ( 13 @,@ 000 kJ ) diet . This was followed by six months of an 1 @,@ 800 calories ( 7 @,@ 500 kJ ) diet , fewer calories than provided by the famine diet experienced by the civilian population in wartime Europe . The research documented the men 's ability to maintain physical output and the psychological effects such as introversion , lethargy , irritability and severe depression . The study then followed the men 's long recovery as they returned to a normal diet and regained the weight lost during the experimentation . 
