The Minnesota starvation experiment has given a lot of helpful insights in the impact of a restrictive diet and the recovery process. It is a medical experiment conducted by Ancel Keys in 1944. He wanted to do researches about the impacts of starvation on the humans body to develop helpful countermeasures so the population could recover the fastest and safest way after the second worldwar.
the procedure of the Minnesota Starvation experiment
The test subjects were 36 physically and mentally healthy men and the experiment consisted of four phases:
1 ) a 12 week control period, in which the normal eating behaviours of the subjects were observed. The average calorie of the participants has been 3500kcals.
2 ) a 24 week semi-starvation period in which the man were restricted to approximately 1600-1800 kcals per day. They ate breakfast and lunch, mostly carbohydrates (bread, root vegetables and potatoes) and very low in protein to mimic a European diet during the world war.
3) a 12 week refeeding period, in which the group has been divided into five groups, but the men did not know in which group they were in.
One whose calorie intake was gradually increased by 400kcals, one by 800, one by 1200 and one by 1600.
4) A small amount of participants (12) stayed at the residential eight weeks longer and were able to eat unrestricted.
Results of the Minnesota Starvation experiment
The Minnesota starvation experiment has shown, that starvation dramatically alters personality and that nutrition affects not only the body, but also the mind.
- most participants lost >25% of their weight
- many experienced anemia, fatigue, apathy, extreme weakness, irritability, neurological deficits, and lower extremity edema
- basal metabolic rate dropped below 40% than normal
- sex drive disappeared
- decreased strength (muscle mass)
- “dizziness, extreme, tiredness, muscle soreness, hair loss, reduced coordination, and ringing in their ears”
- skin changes
Those who are starving are ready to argue on little provocation, but they usually regret it immediately.Men in Hunger Booklet
- enthusiasm for the experiment waned
- higher irritability and impatience
- more introverted, less interest in human interaction, increased need for quiet and privacy
- food obsession: eating became a ritual, started eating slower, collecting cookbooks
- even years after the experiment participants were afraid, that food was taken away from them
Changes in eating behaviour
“it made food the most important thing in one’s life-
. . . food became the one central and only thing really in one’s
life. And life is pretty dull if that’s the only thing.” (Harold Blickenstaff)
Psychologically, during the semi-starvation phase, the hunger made the men obsessed with food. They would dream and fantasize about it, read and talk about it constantly and excessively savor the two meals a day they were given. One started to steal food, whilst another was eating food out of garbage cans.
Keys convinced twelve participants to stay longer, so he could monitor them during an unrestricted rehabilitation phase. “Left to their own devices, Keys observed these men consume over 5000 calories a day, on average. And on occasion, some of them feasted on as many as 11,500 calories in a single day. For many months, the men reported having a sensation of hunger they couldn’t satisfy, no matter how much they ate.“
This phenomenon we are calling now extreme hunger.
Meaning for eating disorder recovery
“In some cases, sharing the details of the experiment with patients has proved therapeutically beneficial in explaining the effect of starvation on their own bodies.” So, what is it, that we can use for the process of recovering from an restrictive eating disorder?
The metabolism is adaptive
Your metabolism isn´t broken. It just adapted to your current calorie intake. When you start increasing it again – it will adapt to this situation as well. The reason behind this is, that your body wants to be in balance – within your set point weight range. Physiologically this means, your metabolic rate will rise as you gain weight in an effort by your body to burn more calories and bring your weight down to it’s preferred set point. And being small results in a lower metabolic rate so it is easier to gain weight back to your body’s preferred set point.
With other words: the “body flame [were] burning as low as possible to conserve precious fuel and still maintain life process”
4000 kcal to refeed
In the refeeding process the men in the lower calorie groups haven´t shown any improvement. They were still extremely hungry, were thinking about food all day and have not shown a increase of their basal metabolic rate. Even providing them with extra vitamin and protein supplements did not help. He eventually concluded that in order to recover from starvation, a person needs around 4000 calories a day to rebuild their strength.
dieting increases the amount of body fat over time
The men lost about 70% fat during the semi-starvation and 40% muscle mass. During the refeeding process the “new weight” was mostly fat, even though within eight months most of the participants were at 100% of their original body weight, the fat mass was approximately 140%. The body does this in order to protect itself from a future famine. Allow your body to adjust, the participants went back to their normal fat-muscle ratio after 6 months of the refeeding process
Keep in mind – your body can recover and balance out itself. But only if you recover and never restrict again. Keep pushing through.
uncontrollable food obsession
restricting triggers feeling obsessed with food, bingeing and other abnormal eating behaviours. In order to stop bingeing/ overeating you have to stop all kind of restricting. (Especially mental restriction)
- Keys, A. (1944) Will You Starve That They Be Better Fed? Brochure dated May 27, 1944.