Friday, July 2, 2010

Semistarvation Experiments in WWII

This morning I had a chance to read this fascinating article about Ancel Keys' semistarvation experiments of conscientious objectors toward the end of World War II.

For the study, 36 healthy young men who had been excused from armed service for ethical objections to killing agreed to a year long diet of sorts that would include 3 months of preparation, 6 months of semistarvation, designed to make the men lose 25% of their body weight, and then 3 months of refeeding. The purpose of the study was to determine how people would react under such conditions, and then also to learn how to safely and successfully refeed starving populations. The men were highly motivated for the study, and their purpose was to help their country and the young men who were fighting overseas who might face starving conditions themselves.

The young men lived in a dorm at the University of Minnesota, and in addition to their restricted diet, they were required to walk 22 miles a week. All their food was prepared in a dormitory kitchen, and once the starvation began, each man's calories were adjusted every Friday to meet a weight loss goal of 2.5 lbs (1.1 kg) per week. Their average daily calories during the semistarvation period was about 1600 calories a day (they ate approximately 3200 calories daily before the study). I find the number 1600 calories especially compelling, for a standard weight loss diet recommended for a woman is about 1200 calories daily. Their food consisted of what might have been available in war-torn Europe at the time - potatoes, turnips, rutabagas, dark bread, macaroni, small glasses of milk, chicken, toast with a small smear of jam, those kinds of things.

What was it like for them? Well, horrible. They described lethargy, irritability, anxiety that approached each time they were to learn how much they were allowed to eat the following week. They had to institute a buddy system so that none of the men were allowed to leave the dormitory alone, as one man went off diet and had to be excused from the study. They had dizziness, cold intolerance (requesting heavy blankets even in the middle of summer), muscle soreness, hair loss, reduced coordination, edema, and ringing in the ears. Some had to withdraw from their university classes because they did not have the capability to concentrate. Their sex drive disappeared. They became obsessed with food, eating with elaborate rituals (which eating disorder patients also do) and adding water to their plates to make the food last longer. Many collected cookbooks and recipes. One man, tempted by the odor from a bakery, bought a dozen doughnuts and gave them to children in the street just to watch them eat. Originally, the participants were allowed to chew gum, but when many of the men went to chewing about 40 sticks a day, it was decided that gum would affect the experiment and it was disallowed.

Only 32 of the original 36 completed the semistarvation period. One man who broke diet admitted to stealing scrapings from the garbage cans, stealing and eating raw rutabagas, and stopping at shops to eat sundaes. Two of the men suffered severe psychological stress - one became suicidal, and another began self-mutilating, and both had to be taken to a psychiatric hospital (the details or the mutilation and suicidality are not mentioned in the article I cited at the top of the post, but are described in Good Calories, Bad Calories by Gary Taubes. The book Depression-Free, Naturally: 7 Weeks to Eliminating Anxiety, Despair, Fatigue, and Anger from Your Life describes one man cutting off three of his fingers).

The 3 month refeeding period involved trying several different combinations of protein, vitamins, and levels of calories. Dizziness, apathy and lethargy improved first, but persistent hunger, weakness, and loss of sex drive persisted for several months. The men described "a year long cavity" that needed to be filled. The day after they were finally released from the study, one of the men was hospitalized to have his stomach pumped after binging. In the aftermath of the study, "many, like Roscoe Hinkle, put on substantial weight: “Boy did I add weight. Well, that was flab. You don’t have muscle yet. And get[ting] the muscle back again, boy that’s no fun.”" None who were interviewed in their 80s felt there was any lasting medical harm, once they'd recovered.

If you have a moment, the article is definitely worth a read, and it's only 6 pages long. Much easier to digest than Keys' 1385 page textbook based on the research, The Biology of Human Starvation (which I must admit, I have not read, and given the height of the stack of books on my nightstand, I will not be reading any time soon).

Again, what strikes me the most about this study is how close it is to the standard recommendations for weight loss today (500-1000 calorie deficit daily for goal of 1-2 pounds lost a week, plus moderate exercise). The difference is by degree (1700 calorie deficit daily for goal of 2.5 pounds lost a week), and the fact that the men were normal weight when they began the study. But this strict diet sent 6% of the participants to the psychiatric hospital - and these were highly motivated, healthy young men! There is also a marked contrast between the psychological states in this long-term semi-starvation and reports of shorter-term water fasts. And what about bariatric surgery patients - the voluntary surgery leads to forced, sustained semi-starvation, after all. This study shows an improved quality of life and far greater weight loss compared to obese controls, and this study shows improved mental health at 6 months and 12 months post surgery, (though they used a questionnaire called the "SF-36" in which 36 questions somehow covered eight dimensions of "physical functioning, role limitation due to physical health problem, bodily pain, social functioning, general mental health, role limitations due to emotional problems, vitality/energy/fatigue, and general health perceptions.") Finally, this study shows sustained improvement in depression after bariatric surgery with subsequent weight loss, even after 4 years. The differences in the amount of adipose tissue available for fuel may make a real difference (I sincerely doubt this is the case, or else it would be easy to lose weight if one were obese), and most post-bariatric surgery diets it seems to me must be higher in protein than the Ancel Keys diet. Also, there is suspected to be an immediate hormonal change in the body after a gastric bypass, and this may affect satiety and the perception of starvation as the bodyfat set point is suddenly adjusted much lower.

All told, prolonged semi-starvation on turnips and dark bread is not something I would recommend for anyone, if you can avoid it. Perhaps Mrs. Ancel Keys said it best, when she described the effects of the experiment on her husband: "“Mrs. Keys said that Dr. Keys went through terrible times during the experiment as we lost weight and became gaunt and so on. And he would come home and say, ‘What am I doing to these young men? I had no idea it was going to be this hard.’ ”


  1. Your post reminds me of similar behaviours you see in the many body builders I have been around during my time working in the fitness industry. In particular the women, panicking as they get closer to competition time and their body fat isn't dropping fast enough, will really screw their calorie intake right down, probably to 1600kcal or lower. They also engage in their daily strength training session and do daily cardio (typcially low intensity walking or cycling).

    Their personalities completely change. They become lethargic (they will complete training but often spend the rest of the day sleeping, sitting, etc - they display marked economy of movement), irritable, and anxious around food and social settings.

    Those of us not into body building loved it as most of the women would become seriously obsessed with food and do lots of baking, which they would bring into the gym to give to us personal trainers (donuts to kids?)!

    Typcially after the competition (which saw many of them on stage looking scrawny through their upper body due to extreme loss of muscle mass & flabby through their bottom half as their body's fought hard not to release that fat), they would binge for a week, struggling with bloating, oedema, food reactions, etc. Bingeing and purging wasn't uncommon.

    They would invariably feel so awful going from eating very cleanly (chicken, broccoli, & rice at every meal anyone?), though very calorie restricted, to eating all manner of wheat & dairy derived rubbish. Within 4 weeks they were typcially trying to go back on the diet again as to them it was the only thing that worked - then they are trapped.

    A friend of mine once competed at just over 80kg and within 2 days the boofheads that trained him were trying to force feed him to push him over the 100kg mark. It was disgusting.

  2. Studies of anorexics show that pharmacological and psychological treatments simply don't work unless there is also sufficient refeeding. The evolutionary imperative is clear - eat!

  3. I wish the article had mentioned how much further they had to reduce calories as the experiment progressed, to see the 2.5 lb weight loss per week. Of if they had to reduce any.

    Keys adjusted caloric intake based on progress towards that goal. Guess I'll have to read the book sometime.

    I read a lot of nutrition and weight-loss blogs and often run across untrained folks who think if an overweight person reduces caloric intake too much, his metabolism simply slows down and he stops losing weight or actually GAIN weight.

    Keys' semistarvation experiment is proof against that idea, as if we needed any. I used to cite the condition of Nazi concentration camp survivors.

    BTW, I googled "evolutionary psychiatry blog" (without the quotes) and you didn't show up in the first 15 pages. Something wrong with this picture. Perhaps your blog is still too young to show early.

    Keep up the good work.


  4. Thanks Steve! We are a young blog. If I find more info on the studies I'll post it. I'm not sure I believe in "starvation mode" so far as gaining weight on insufficient calories. I believe it makes perfect metabolic sense that we would downshift our metabolism in starvation, like these young men did (lethargy, cold), and thus be more efficient at using our calories. But of course we can keep losing - anorexia is a perfect example. We can keep losing to a horrifying extreme. It may take some disordered thinking to do it.

  5. This article is actually pretty funny. A guy who condemns cholesterol and animal fats creates a "recovery" diet for these semi-starved men? Is it really surprising that they didn't recover?


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