Examining the Minnesota Experiment, a study performed in the mid-1940s to determine the effects of starvation, is a sobering task. The data gained by researcher Ancel Keys and his team at the University of Minnesota came at great personal cost to each of the study's participants: The 36 men who endured the testing experienced a tremendous struggle simply to complete the journey.
The purpose of the Minnesota Experiment was to understand more about how to deal nutritionally with emaciated people in Europe after the catastrophe of World War II. The results of the study came a bit late for that, but they do give us insight into the incredibly powerful and negative effects of starvation.
I believe that the effects of starvation in the experiment have strong parallels with the experience of those who starve themselves through anorexia nervosa. The subjects in the Minnesota Experiment had all the advantages of great care and still suffered in brutal ways. Those with anorexia are typically not monitored nearly as well, making the effects of starvation more worrisome.
The Minnesota Experiment's Physical Toll
The 36 men who participated in the study were in their twenties and physically fit. After 3 months of normalizing the participants' eating patterns, each man's food intake was reduced by over 40% and limited to foods that were available in the war-ravaged areas of Europe. They also maintained an exercise requirement of 22 miles of walking per week.
This regimen continued for 6 months. As semi-starvation progressed, the men encountered debilitating physical problems. Their strength lessened. Exhaustion took hold, and they ultimately saw trivial tasks such as stepping up onto a curb as too taxing to attempt. They became skeletal in appearance, their look punctuated by edema in the lower extremities and deteriorating skin. Further, the men tested in the Minnesota Experiment dealt with anemia, slowing of reflexes, sleep loss, and dizziness.
- Compare and contrast with the physical symptoms of anorexia nervosa
Psychological and Behavioral Consequences in the Minnesota Experiment
Perhaps even more disturbing were the changes in personality and attitude that swept through the Minnesota Experiment's test subjects. Over time, participants lost patience with each other far more easily. They compared their rations, becoming frustrated when their food allowances were less than those of others because their rates of weight loss didn't match. Their thoughts of food became obsessions, and they began to eat their rations in ritualistic ways. Some began to collect cookbooks and recipes.
It strikes me that these symptoms seem to have much in common with those of a person struggling with anorexia. And there's a good deal more.
Some of the men experienced distortions in body image. Depression occurred, sex drive plummeted, and relationships with loved ones suffered. Participants even engaged in self-harm in some cases. One participant cut off three of his own fingers.
Finally, and somewhat predictably, some of the men reacted to their small rations with binge eating - just as many people who diet do.
I would suggest that these psychological symptoms are similar to those that manifest in anorexia. With this experiment in mind, some researchers are investigating whether the effects of dieting are particularly prominent in eating disorder development. The link hasn't yet been firmly established, but the Minnesota Experiment raises curiosity: Is there some chicken-and-egg interaction for some between dieting and eating disorders? Do they reinforce each other?
- Compare and contrast with the psychological symptoms of anorexia nervosa
- Compare the fascination with food to the use of "food porn" by those with eating disorders
- Links between eating disorders and obsessive-compulsive disorder (OCD)
Refeeding in the Minnesota Experiment
Unlike anorexia, the Minnesota Experiment included plans to bring the men back to health. Researchers split the participants into subgroups for refeeding, giving each group a different number of calories to see how different rates of food intake affected recovery.
Dr. Keys and colleagues found, however, that restoration was difficult to achieve without significant calories. Keys noted, "The proper level is more like 4000 [kcal] daily for some months. The character of the rehabilitation diet is important also, but unless calories are abundant, then extra proteins, vitamins and minerals are of little value."
Current eating disorder treatment also acknowledges that significant amounts of food (safely consumed to avoid refeeding syndrome) is the best medicine available for acute anorexia. The men in the Minnesota Experiment may not have had eating disorders, but the key element in bringing them back to health was similar to the most important part of recovery from anorexia.
What Have We Learned?
Consuming the limited daily calories given in the Minnesota Experiment can be extremely debilitating in a relatively brief time. The calorie levels closely mirror the recommended intake in many diets on the market today. It's worth questioning whether it makes sense to subject yourself to a practice that has such negative effects on body and mind.
Most sobering is that these men did not have histories of disordered eating. But taking away their food seems to have caused them to look and act as though they were under the influence of anorexia. While we have strong evidence that there is genetic influence in eating disorder development, the Minnesota Experiment reminds us that environments of our own making can also affect us powerfully.
Sources:
Kalm LM and Semba1 RD. "They starved so that others be better fed: Remembering Ancel Keys and the Minnesota Experiment." Journal of Nutrition 135 (2005): 1347-1352.
Szwarc S. "How we’ve come to believe that overeating causes obesity." At junkfoodscience.blogspot.com. Accessed 11 June 2009.
