What was the MN Starvation Experiment?

In 1944, 36 volunteers, all male, walked into the football stadium of the University of Minnesota to begin a year long journey as subjects in a study done by one of the world's most prominent nutrition researchers, Ancel Keys. Along with researcher Josef Brozek, Keys was determined to study the physiological, behavioral and psychological effects of starvation in the hopes of creating a manual for relief workers in World War II after reports of starving populations all over Europe were reaching the US.

Throughout the story I'm about to tell you regarding the findings of this study, I want you to keep one thing in mind. Although this study began during World War II, when nations were severely struck by lack of food, starvation (or semi-starvation as was the actual case when it came to the calories subjects in the study were consuming), isn't something that only happens when a population is out of food due to external factors. 

For the body, a state of semi-starvation (or even starvation) can be self imposed, self inflicted, and thousands are doing it as we speak. As we move forward into the mind-blowing findings of this study (trust me, this is one of the best resources I've found this year when it comes to the effects of dieting), I want you to look at it through the lens of your own stories with food and dieting, or that of anyone you know who has suffered through the perils of disordered eating.

The Minnesota Starvation Experiment has been regarded as the most important study on the psychological, physical and social effects of food restriction, and the manual and two volume book that resulted from this 13 month study is still being used today by relief workers in areas struck by hunger, and it's also a cornerstone in the fields of disordered eating. It's a truly remarkable story that showcases the huge effects that restricting food has on our mental well-being, our social interactions, and of course our physical bodies. In my opinion it's the one book on diets every single person should read before buying any other, and the great news is you'll get to see and read the actual manual at the end of this post if you'd like to go even further.

How did the Minnesota Starvation Experiment Work?

This experiment put the 36 subjects through three different phases of eating:

- An initial phase of 12 weeks feeding them a diet of approximately 3200 calories (the exact amount depended on the person's own physical characteristics.

- This phase was followed by the longest one, 6 months of what they called a "semi starvation diet" in which calories were lowered to 1600. Yes, we will be talking about this calorie amount in a second, and yes, this amount is actually higher than what most current diet books and programs recommend. 

- This was followed by a 3 month rehabilitation phase in which subjects were fed anywhere between 2000 and 3200 calories.

- In the final 8 weeks of the study, participants had unrestricted calories.

During these 13 months, the 36 subjects would live at the university, have about 15 hours a week of work assignments which they themselves chose according to their interests, 25 hours of educational activities also chosen according to their preference, they were required to walk 22 miles (36 Km) a day, keep a journal and eat only the food that was prepared for them, which would be divided between two meals: lunch and dinner. Other than this, subjects led completely normal lives when it came to going outside, living their lives, seeing friends and family, etc.

It's in those 6 months of 1600 calories and in the months that followed where the most interesting findings occurred.

Why study the effects of restriction, dieting and starvation?

Ancel Keys wanted to find out how starvation produced changes in intellect, behavior, motivation, and social changes that affected personality, all in the hopes that this would help them understand how to help populations recover from starvation. Such an important task in the moment in which this study began, since not only were soldiers and entire towns suffering from incredible food shortages but halfway through the study, the war would end and concentration camps filled with holocaust survivors in the worst possible states of malnutrition would be liberated.

Their Findings

Through the six months on the "semi starvation diet" of 1600 calories, changes in the subjects' lives were astounding:

- Physically, they dropped weight dramatically. They suffered from exhaustion, reduced strength, reduced body temperature and heart rate. They looked emaciated and developed edema (swelling) of the feet.

- They began experiencing significant changes in behavior and especially motivation.

- Almost all subjects engaged in strange habits regarding the handling of the food, often times very childlike including playing with it, rearranging it on the plate, creating odd rituals around it, etc.

- There was a severe decline in motivation to do activities they once enjoyed, including engaging in social interactions with people they loved and who they enjoyed spending time with.

- Their libido disappeared.

- When eating, they would lick the plates just to extend mealtime and they retained food in their mouths for prolonged periods of time without swallowing.

- Reported by almost all subjects was the constant daydreaming of food. They became obsessed with food and food related topics. Some began studying cookbooks for hours on end, others collected recipes in strange ways and in a very obsessive manner, and some changed their career paths to be able to work with food constantly.

- There was a severe decline in socialization. Subjects became incredibly irritable around others, especially around mealtime in which subjects required absolute silence and no interruptions in order to perform their new obsessive food rituals. It was their sacred hour and subjects were very much on edge at this time. Noise disturbed them profoundly, and all of this carried on throughout the day since isolation was a common result of the study. Many subjects reported a desire to be alone and not see other people. They developed strong, unfounded, animosity towards strangers, and strong friendships that began in the first phase of the study between the men, ended. They were described in the study as being a "tired, dead, group of men".

- They experienced mood swings, had arguments with others with almost no provocation, and these were followed with almost immediate and very powerful feelings of sadness and remorse.

- They suffered from depression, strong anxiety, feelings of resignation, exhaustion and apathy.

- They all experienced an overwhelming feeling of inertia, and this made many of them put their lives and activities on hold.

- When a participant would, on occasion, cheat on the diet in a small way, they would feel intense remorse and guilt.

- Subjects reported a decrease in their mental abilities, even though these were normal when tested. Meaning they had the feeling of having cognitive decline even if it wasn't so.

- Their affection towards others decreased and they were uninterested in enjoying activities with others unless they involved the planning of how to get more food.

- They reported a lack in confidence and felt insecure.

- On some instances participants reported a sudden feeling of elation or being "high", mostly felt by the men during a moment of thinking they had gotten used to the small rations of food. This feeling wouldn't last though, and it produced a deep sense of discouragement and pessimism.

- Some men began creating odd behaviors like stealing, some stole food, and one participant was found stealing coffee cups from coffee shops and collecting them. Odd collections of objects and especially recipes were very present among the men, and many of the men expressed that their moral guidelines had lessened.

- They would have very low concentration, having to stop their work or educational activities constantly to daydream about food or obsess over moments in the past in which they missed or declined an opportunity to eat something. 

- They would plan their next meal meticulously even though their meals were chosen and prepared for them. They would obsessively plan how they would fix certain ingredients on the plate (some began adding water to potatoes to increase the amount). They would plan out what utensils they would use and what they would start eating first, often making detailed written notes of their plan so as not to forget it, sometimes only to change it completely once the meal was in front of them. This planning and daydreaming of food was sometimes reported to last 1 or 2 to 3 hours at a time.

- Many subjects became interested in nutrition.

- Some reported an inability to make decisions, even simple ones like deciding what corner to take while walking outside. This was also reported by the men in saying they couldn't decide what words to use next in conversation and therefore their solitary behavior increased as time passed.

The effects were staggering.

Recovery

Although during the rehabilitation phase of the experiment many recovered physically as soon as more calories were re-introduced, the behavior and psychological changes remained, often times for years after the study was over, especially when it came to people's relationship with food and understanding of hunger and fullness cues. 

In some cases, their mental states became aggravated during recovery showing signs of aggression and very strong mood swings.

Fortunately, their social behavior and mood eventually started stabilizing, but in most cases never returned to its normal state and caused overeating and binge eating.

Through the different recovery diets and supplements tried during the recovery phase, the key to rehabilitation was simply more food, aka these men simply needed calories. No mystery around it, just more food.

The subjects that slowly started recovering reported a feeling of "a great awakening", a larger appreciation of experiences, the motivation to work returned, and they reported having a feeling of aliveness that had been completely missing before.

Simply put they were men who had postponed their living to only focus on food. Now they were coming back to life.

Powerful stuff.

All because of eating 1600 calories, a number that is quite high when you take a look at the calorie recommendations of many popular diet programs out there.

The findings of this study are still being used by relief workers today in starving populations and it is still considered the most expansive study on starvation done to date. They were published first as a manual for relief workers on the field called "Men and Hunger: A psychological manual for relief workers", and in 1950 as a two volume book titled "The Biology of Human Starvation".

Pretty mind-blowing when you think of the profound psychological effects of feeling restricted, some of which will also be reported by anyone who has ever been on a diet: constant mood swings, food obsessions, binge eating and overeating, isolation from others, constant planning of meals and developing rituals around it. The only difference is we do this to ourselves, often for no pressing medical matter, but to meet beauty ideals that might not even be attainable.

The message in this study is so powerful I highly recommend reading some of the actual participants' experiences, which you can take a look at in the actual manual here (it takes a while to load so just be patient, it's worth it!).

I've said it many times before, and I'll keep repeating it until all of us change that belief of needing to constantly be "fixing" and restricting food, into one of having a better relationship with food. We all have eating guidelines we follow, or a way of eating that is unique to us, but when we step into restriction, we now know the results can be devastating for our emotional, social and physical well-being, which is why I'm still here, on this mission of giving you tools to eat healthily, while keeping everything in balance and taking restriction out of the equation for good.

I believe the work of Ancel Keys is something that can really help a lot of people suffering with food and weight issues, so please share this post if you believe it could help someone you love who is struggling and on the dieting rollercoaster.

Want to take your journey even further? 

Take a look at our online program My Brownble, where we teach you how to cook amazing vegan food without added restriction, and help you on that ongoing quest of finding peace with food.

In and out of the kitchen. 

...and there's so much more. You can check out all the details here.