The psychology of hunger

In November 1944, 36 young men took up residence in the corridors and rooms of the University of Minnesota football stadium. They were not members of the football team. Rather, they were volunteers preparing for a nearly yearlong experiment on the psychological and physiological effects of starvation. Known as the Minnesota Starvation Experiment, the study was a project of the newly established Laboratory of Physiological Hygiene at the University of Minnesota, an interdisciplinary research institution with an emphasis on nutrition and human biology.

At the time, World War II was raging around the world, and so, too, were hunger and starvation. Over the centuries, people had recorded anecdotal reports of the effects of famine and starvation, but there was little in the scientific literature that described its physiological and psychological effects. Just as important, doctors and researchers didn't know how to help people rehabilitate and recover from starvation.

Eager to take on the challenge was Ancel Keys, PhD, the physiologist in charge of the Minnesota lab. The lab's chief psychologist, Josef Brozek, PhD, was responsible for gathering the psychological data on the effects of starvation. Brozek had completed his doctoral degree in 1937 at Charles University in Prague with interests in applied psychology, physiology and physical anthropology, and joined the Minnesota lab in 1941.

Among his duties, Brozek assisted in recruiting subjects for the study. In previous nutrition studies at the lab, Keys had drawn subjects from the ranks of the Civilian Public Service (CPS). During World War II, the CPS provided conscientious objectors an alternative to military combat service. These objectors were often referred to as human guinea pigs because of their willingness to serve in medical experiments. Keys knew from experience that many conscientious objectors were eager to do meaningful work that would benefit humanity and was confident that the starvation experiment would attract the needed volunteers.

Subject selection was stringent. Subjects had to be male, single and demonstrate good physical and mental health (largely based on the newly developed Minnesota Multiphasic Personality Inventory). They also had to show an ability to get along well with others under trying circumstances and an interest in relief work. The final 36 men were selected from more than 200 volunteers and in November 1944 made their way to the University of Minnesota to begin their service.

The research protocol called for the men to lose 25 percent of their normal body weight. They spent the first three months of the study eating a normal diet of 3,200 calories a day, followed by six months of semi-starvation at 1,570 calories a day (divided between breakfast and lunch), then a restricted rehabilitation period of three months eating 2,000 to 3,200 calories a day, and finally an eight-week unrestricted rehabilitation period during which there were no limits on caloric intake. Their diet consisted of foods widely available in Europe during the war, mostly potatoes, root vegetables, bread and macaroni. The men were required to work 15 hours per week in the lab, walk 22 miles per week and participate in a variety of educational activities for 25 hours a week. Throughout the experiment, the researchers measured the physiological and psychological changes brought on by near starvation.

During the semi-starvation phase the changes were dramatic. Beyond the gaunt appearance of the men, there were significant decreases in their strength and stamina, body temperature, heart rate and sex drive. The psychological effects were significant as well. Hunger made the men obsessed with food. They would dream and fantasize about food, read and talk about food and savor the two meals a day they were given. They reported fatigue, irritability, depression and apathy. Interestingly, the men also reported decreases in mental ability, although mental testing of the men did not support this belief.

For some men, the study proved too difficult. Data from three subjects were excluded as a result of their breaking the diet and a fourth was excluded for not meeting expected weight loss goals.

The men and the study became subjects of national interest, even appearing in Life magazine in 1945. But in some ways, world events overtook the study. The war in Europe ended on May 8, 1945, barely halfway through the starvation phase of the experiment. Keys and the men worried that the data they had sacrificed for would not get to relief workers and the starving people they wished to serve in time to help them. Relief efforts were underway and there was no clear guide for rehabilitating those who were starving.

In response, members of Keys staff prepared a 70-page booklet, Men and Hunger: A Psychological Manual for Relief Workers. The book provided practical advice based on lessons learned in the lab.

The Minnesota Starvation Experiment ended in October 1945. Its results painted a vivid picture of the physical and psychological decline caused by starvation and offered guidelines on rehabilitation. In the restricted rehabilitation, calories were increased in increments. The experiment also looked at unrestricted rehabilitation and — even though participants were warned against it — some engaged in extreme overeating. Of the various diets and supplements that were studied during the rehabilitation phase of the experiment, the most reliable weight-gain strategy was high caloric intake. Simply put, starving people needed calories. Food and lots of it was the key to rehabilitation. It was as true for those released from the laboratory in Minnesota as it was for those freed from the privations of war in Europe.

In 1950, Keys, Brozek and other members of the team published their data in the two-volume set "The Biology of Human Starvation," which is still a landmark work on human starvation. The men who served as subjects went their separate ways, some into relief work, the ministry, education and other service-oriented occupations. Brozek, who had developed an interest in the history of psychology, would go on to Lehigh University and became a recognized psychology historian. Keys, who is well-known for his work on the Mediterranean diet, is also remembered for popularizing the body mass index. His contributions and visibility were significant enough to earn him a place on the cover of Time magazine in 1961.

The story of the Minnesota Starvation Experiment is many stories rolled into one. It reminds us of the privilege we have; most of us can avoid the unpleasant sensation of hunger by simply reaching for something to eat. Hunger is debilitating and tragic, all the more so when it is created by human affairs. The Minnesota Starvation Experiment also tells the story of service and sacrifice among those who served in the Civilian Public Service and raised questions about the ethics of human experimentation. Mostly, it reminds us that in psychology studies of mind and body, science and practice can converge to deal with real problems in the real world.

David Baker, PhD, is the Margaret Clark Morgan executive director of the Center for the History of Psychology and professor of psychology at the University of Akron. Natacha Keramidas is a graduate assistant at the Center for the History of Psychology and a PhD student in the collaborative program in counseling psychology. Katharine S. Milar, PhD, is historical editor for "Time Capsule."