Minnesota Study

The men’s change in relationship to food was one of the most striking results of the experiment. They found it increasingly difficult to concentrate on more normal things, and became plagued by persistent thoughts of food and eating. Food became a principal topic of conversation, of reading, and of daydreams. Many men began reading cookbooks and collecting recipes, whilst others became interested in collecting various kitchen utensils. One man even began rummaging through rubbish bins in the hope of finding something that he might need. This desire to hoard has been seen in both people and animals that are deprived of food. Although food had been of little interest to the men prior to entering the experiment, almost 40% of them mentioned cooking as part of their post experiment plans. Some actually did change their career to a career focussed on food once the experiment was over.

The men’s eating habits underwent remarkable changes during the study. Much of the day was now spent planning how they would eat their allocated food. Plus, in order to prolong their enjoyment of the food eaten, it would take them vastly longer amounts of time to eat a meal. They would eat in silence and would devote their total attention to the consumption of the food.

The subjects of the study were often caught between conflicting desires to gulp down their food ravenously and to consume it so slowly that the taste and smell of each morsel of food would be fully appreciated. By the end of the starvation period of the study, the men would dawdle for almost two hours over a meal that they previously would have consumed over a matter of minutes.

Another common behaviour was that they would make unusual concoctions by mixing different foods together. Their use of salt and spices increased dramatically, and the consumption of tea and coffee increased so much that they had to be limited to 9 cups per day. The use of chewing gum also became excessive and also had to be limited.

During the 12^th week re-feeding phase of the experiment, most of these abnormal attitudes and behaviours to food persisted. Some of the men had more severe difficulties during the first six weeks of re-feeding. The free choice of ingredients stimulated “creative” and “experimental” playing with food; for example, licking off plates and very poor table manners persisted.

Binge Eating

During the restrictive phase of the experiment, all of the volunteers reported feeling more hungry. Whilst some appeared able to tolerate this fairly well, for others it created intense concern or even became intolerable. Several of the men failed to stick to their diet and reported episodes of binge eating followed by self-reproach. While working in a grocery store, one man:

- suffered a complete loss of willpower and ate several cookies, a sack of popcorn, and two overripe bananas before he could ‘regain control’ of himself. He immediately suffered a severe emotional upset, with nausea, and upon returning to the laboratory he vomited. He was self deprecatory, expressing disgust and self criticism.

After about five months of re-feeding, the majority of the men reported some normalisation of their eating patterns, but for some the difficulties in managing their food persisted. After eight months, most men had returned to normal eating patterns, although a few still had abnormal eating patterns. One man still reported consuming around 25% more than he did prior to the weight loss and “once he started to reduce but got so hungry he could not stand it”.

It is important to remember that the subjects were psychologically very healthy prior to the experiment but most experienced significant emotional changes as a result of semi-starvation. Many experienced periods of depression; some brief whilst others experienced protracted periods of depression. Occasionally elation was observed, but this was inevitably followed by “low periods”. The men’s tolerance that had prior to starvation been high was replaced by irritability and frequent outbursts of anger. For most subjects, anxiety became more evident; many of the formerly even-tempered men began biting their nails or smoking if they felt nervous. Apathy was a common problem, and some men neglected various aspects of their personal hygiene. Most of the subjects experienced periods during which their emotional distress was quite severe, and all experienced the symptoms of “semi-starvation neurosis” described above.

Both observation and personality testing showed that the individual emotional response to semi-starvation varied considerably. Some of the volunteers seemed to cope very well whilst others displayed extraordinary disturbance following weight loss. As the emotional difficulties did not immediately reverse once food was in ready supply, it may be assumed that the abnormalities were related more to body weight than to short term calorie intake. So, we can draw the conclusion that many of the psychological disturbances seen in anorexia and bulimia nervosa may be the result of semi-starvation process itself.

Most of the volunteers experienced a large shift in their social behaviours. Although originally quite gregarious, the men became progressively more withdrawn and isolated. Humour and a sense of friendship and comradeship diminished markedly amidst growing feelings of social inadequacy.

Social initiative especially, and sociability in general, underwent a remarkable change. The men became reluctant to plan activities, to make decisions and to participate in group activities…they spent more and more time alone. It became ‘too much trouble or too tiring’ to have contact with people.

The volunteers’ social contacts with women also declined sharply during semi-starvation. Those who continued to see women socially found that the relationships became strained. One man described his difficulties as follows.

“I am one of about 3 or 4 who still go out with girls. I fell in love with a girl during the control period but I see her only occasionally now. It is almost too much trouble to see her even when she visits me in the lab. It requires effort to hold her hand. Entertainment must be tame. If we see a show the most interesting part of it is contained in scenes where people are eating.”

One subject graphically stated that he had “no more sexual feeling than a sick oyster”. During the rehabilitation period the men’s sexual interest was slow to return. Even after three months they judged themselves to be far from normal in this area. However, after eight months some or virtually all of the men had recovered their interest in sex.

The volunteers reported impaired concentration, alertness, comprehension and judgement during semi-starvation.

As the six month of semi-starvation progressed, the volunteers exhibited many physical changes including the following: gastro-intestinal discomfort, decreased need for sleep, dizziness, headaches, hyper-sensitivity to noise and light, reduced strength, oedema (an excess of fluid causing swelling), hair loss, decreased tolerance of cold temperatures (cold hands and feet) and parasthesia (abnormal tingling or prickling sensations, especially in the hands and feet). There was an overall decrease in metabolism (decreased body temperature, heart rate and respiration). As one volunteer described it, he felt as if his “body flame were burning as low as possible to conserve precious fuel and still maintain life processes”.

During rehabilitation, the metabolism speeded up again, especially in those who had the larger increases in food intake. Subjects who gained the most weight described being concerned about their increased sluggishness, general flabbiness and the tendency for the fat to accumulate around the stomach and buttocks.

These complaints are very similar to those that people with bulimia and anorexia describe as they gain weight. However, after approximately a year the men’s body fat and muscle levels were back to their pre-experiment levels.

In general, the men responded to semi-starvation by reducing their activity levels. They became tired, weak, listless, apathetic and complained of a lack of energy. Voluntary movements became noticeably slower. However, according to the original report,

“some men exercised deliberately at times. Some of them attempted to lose weight by driving themselves through periods of excessive energy in order to either obtain increased bread rations… or to avoid reduction in rations”.

This is similar to the practice of many patients, who feel that if they exercise strenuously they can allow themselves a bit more to eat.