What can we Learn From the Minnesota Experiment?

Thanks to Hannah Whybrow for this great summary of the infamous Minnesota Experiment. We'd love to hear your thoughts about it:

In 1944, 36 men, with good physical and mental health, volunteered to undergo a period of semi starvation.

This study, now known as the ‘Minnesota Experiment’, hoped to monitor the effects of starvation and improve post-war rehabilitation for malnourished individuals worldwide.

After six months of limited calorie intake, whereby participants lost 25% of their body weight, diets were controlled for a further three months of restricted rehabilitation.

For the final eight weeks of the study, the men were given no calorie limits and able to make their own food choices.

Each week throughout the experiment, the men were required to work 15 hours in the lab, spend 25 hours in educational activities and walk 22 miles; in other words, they had to maintain a regular routine and lifestyle, despite the nutritional changes they were experiencing.

The results of the study, published in a 1,385-page book, ‘The Biology of Human Starvation’ documents the only controlled scientific accounts of the physical and physiological effects of starvation on humans.

Ethical issues aside, it contains some crucial findings to help us better understand what reducing food intake does to us, physically, mentally and emotionally.

Physical Changes

Besides from visible weight loss and lower energy levels, the men experienced significant decreases in strength, stamina, body temperature, heart rate and sex drive. Gastrointestinal discomfort, dizziness, hair loss and anaemia were also common.

Mental Changes

Hunger made the men obsessed with food: they would fantasise about it, read recipe books in their free time, made meals last for hours or collect food-themed items. Their preoccupation with food made it difficult for some of them to concentrate and they reported a decline in mental ability (although their performance on tests remained stable).

Emotional Changes

The men experienced a variety of emotional difficulties including irritability, depression, hysteria, social withdrawal and apathy. These feelings intensified during the rehabilitation phase, compounded by reported guilt for eating previously illicit foods and a rise in body image concerns amongst the participants.

For those of us within the eating disorder community, none of these findings might be surprising – we may have seen these effects on ourselves or our loved ones. So why does the Minnesota Experiment still matter?

For me, there are a few key takeaways that can inform how we think about eating disorders, treatment and recovery:

• Food is essential. When I first read up about the Minnesota Experiment, I was shocked by the calorie limits placed on the men. Not because the number was so low; on the contrary, I was astounded to realise that it was almost double the figure recommended by the dieting apps I had subscribed to throughout my teenage years. And yet, the study unequivocally demonstrates that restricting food is harmful, even to those who are not predisposed to disordered eating. As somebody who has often been willing to pursue mental recovery from my eating disorder, but struggled to reconcile this with increasing calories, the Minnesota Experiment reinforces a crucial facet of recovery: you cannot escape from an eating disorder, mental distress and intrusive thoughts if you are still depriving your body essential nutrients and sufficient calories.

• However… treatment is not a silver bullet and increasing food intake cannot immediately make an eating disorder go away. Yes, eating is essential for physical and psychological wellbeing. However, even if you are following a food plan, eating three meals and two snacks a day, not exercising and putting on weight, the physiological effects of the eating disorder can continue. The Minnesota experiment observed that following their starvation period, participants engaged in binging, purging or restrictive behaviours. Moreover, participants’ wellbeing declined as food intake increased. Whilst starvation can numb feeling, as the body regains strength and emotions return, it can be overwhelming for individuals. So, whilst food is crucial, equally important is emotional support and therapy. Physical recovery is often quicker than mental recovery!

• You are not ‘obsessed’ with food. I remember worrying that I had no personality, was a narcissist or simply out of control because my mind was so preoccupied with thoughts about food and my body that I struggled to think about anything else. I felt like a shell of the person I used to be and wanted to become. The Minnesota Experiment demonstrates that a preoccupation with food is the body’s natural way of managing malnourishment. However, this does not mean that you will never be able to trust yourself around food again. Whilst it did take the participants time to repair their relationship with food and recognise and trust hunger cues, they were able to go on and lead healthy and successful lives. Three men even utilised their newfound interest in food to become professional chefs. The Minnesota Experiment demonstrates the harm that starvation can cause, yet it also indicates that these effects can be counteracted. In other words, recovery is possible!