The Biology of Human Starvation: Volume II
By Ancel Keys, Josef Brozek, Austin Henschel, Olaf Mickelsen and Henry Longstreet Taylor (The University of Minnesota Press, 1950)
WARNING: This review contains descriptions of self-harm, mentions of suicidal ideation and other dangerous behaviour
“Hungry people will not endure reason, they will not listen to justice, nor will they bend to any prayer for mercy”
Ancel Keys ends his account of the human experience of starvation with four quotes, including this from Seneca. It seems an apt way to begin this review of the second volume of The Biology of Human Starvation, which mainly looks at the extraordinary psychological effects of malnutrition in humans.
The Biology of Human Starvation contains the results of the post-war Minnesota Starvation Experiment (MSE), the most comprehensive study into human starvation ever undertaken. Keys and his co-authors combine these results with other available material and set them within the context of man’s experience of famine throughout recorded history.
Famine has shaped the human experience in dramatic ways — resulting in migration, war, and the development of agriculture and with it civilisation. What the MSE showed, among other things, was that famine has also left a blueprint within our DNA for how to survive in times of scarcity. Our bodies — and brains — are programmed to react in a certain way to a lack of food, to adapt in order to stay alive.
The Minnesota study, and other accounts of starvation that Keys cites, clearly shows that eating too little food affects your brain in a surprisingly short space of time — causing dramatic changes in personality, inducing bizarre behaviours and sometimes leading to violent thoughts and even criminal activity. The effects of starvation on the brain are wide-ranging, sometimes shocking — and reflected to a great degree in people with anorexia nervosa.
In fact, it’s clear on reading the book that there is not necessarily as big a difference between the mental effects of ‘normal’ starvation and those of anorexia nervosa as has been traditionally thought. There are some key differences, of course, and they are important as they serve to maintain the illness, but most of the psychological and behavioural traits seen in anorexia can be explained as the brain’s normal response to a restricted diet.
In fact, the results are so striking that it is odd to me that this is not something that is better understood. After all, we’ve had the results of Keys’ incredible work for over 80 years. This aspect of the study has perhaps fallen victim to the lobbying by so many for so long to frame anorexia as a purely psychological disorder which can be explained by external influences — societal messages, traumatic experiences and so on. This study shows that it’s far more likely that most of the answers lie within.
‘Normal’ Starvation Versus Anorexia Nervosa
In Volume II, I noted 28 psychological and behavioural effects of starvation in the men in the MSE that are also seen in people with anorexia nervosa or other restrictive eating disorders. Some were seen in just one subject; some were observed in, or recorded by, many or most of the men:
1 Depression
Perhaps the outstanding feature in both famine and the Minnesota Experiment is depression and apathy, writes Keys. Many of the men in the MSE scored highly for depression during the starvation phase and early in rehabilitation. Depression was the fourth largest change observed during the MSE after basal metabolic rate, haemoglobin and endurance time. Some of the subjects became more depressed during the first weeks of rehabilitation — not unlike people in recovery from anorexia. Furthermore, the changes in the depression score on Keys’ tests during the period of rehabilitation were substantially in direct proportion to the level of caloric supplementation. Those who received more calories recovered from depression faster than those who were on a more restricted diet during early recovery. Once again, there is evidence that diving in — although scary — is ultimately less painful than going in bit by bit.
2 Food Obsession
Keys shows a fundamental misunderstanding of anorexia nervosa in the book when he says: The only known invariable difference between the psychological characteristics of anorexia nervosa and famine is the latter’s continual hunger and absorption with food. Of course, people with anorexia are also consumed by thoughts about food and experience hunger, though perhaps slightly differently to people without anorexia.
In a precursor to the MSE, the Carnegie Experiment, the men were bothered by persistent thoughts about food and eating. In the MSE Food… became the principle topic of conversation, reading, and daydreams for almost all of the Minnesota subjects… Cookbooks, menus and information bulletins on food production became intensely interesting to many of the men… This lasted for months into rehab: By week 20 food was still a vital concern and centre of interest for 11 of the 27 men.
Here lies further evidence that allowing sufficient time for the brain of someone with anorexia to repair after weight gain is crucial. If the men in the study were still experiencing obsessive thoughts about food after five months of re-nourishment, why are we surprised when someone with anorexia does not instantly recover when they gain some weight and begin eating slightly more food?
3 Careers in Food
Anecdotal reports of people with anorexia taking jobs which mean they are working with food are fairly common. This was no different for the men in the MSE. During the study some altered their career paths, making plans to become cooks or go into agriculture and food production.
4 Hypochondria
While starvation is obviously an enormous threat to health, some with anorexia can develop a type of hypochondria that is not necessarily directly related to the effects of malnutrition. I have seen this in my daughter, who worries about any minor ailment but seems not to see the enormous elephant in the room of malnutrition. Keys notes that in some societies anxiety about food is a potent and persistent cultural factor which has shaped behaviour. He cites a study from 1939 by Kardiner, who analysed a particular form of hypochondriasis in the Marquesan Islanders. This was traced to a chronic type of hunger anxiety.
5 Irritability
In the Carnegie Experiment, the malnourished men became irritable and were easily annoyed. Keys describes his subjects as becoming hyper irritable. In the first six weeks of rehabilitation, some became more irritable than during the semi-starvation phase. One of the things many first notice when a loved one develops anorexia is an uncharacteristic bad temper, and this is often heightened initially with re-nourishment.
6 Chewing Gum
In the absence of sufficient food, many men in the MSE began to chew vast amounts of gum — in one case up to 50 packs a day. This is something that some who develop anorexia also seem to turn to.
7 Drinking Coffee
The men in the MSE drank vast amounts of coffee — 15 or more cups a day before a limit was set to nine — and demanded that food and beverages be very hot. Again, this is typical of someone with anorexia. I suspect the caffeine provides energy, the heat is warming and the volume of liquid staves off hunger pangs to some extent.
8 Playing with Food for Lengthy Periods
As the starvation progressed, the number of men who toyed with their food increased. Keys cites a historic example of this (Friedrich, 1950). Prisoners of war in a Russian hospital were observed playing with their food for hours. In the MSE Towards the end of starvation some of the men would dawdle for almost two hours over a meal… To increase the pleasure of eating, they would do much planning as to how they would handle their day’s allotment of food. People with anorexia often lengthen their mealtimes, cut their food into small pieces or otherwise play with it.
9 Intolerant of Food Waste
The men in the MSE became intolerant of food waste. Like many psychological effects, this was long lasting. During the re-nourishment phase of the study, this continued, with the men licking their plates so that they didn’t miss a single crumb. They showed an irrational fear that food would not be available. By week 15 of the rehabilitation phase, one man said he still felt a slave to food and another was still nearly obsessive about food waste.
10 Violent Urges
Several of the men developed strong urges towards violence, but these were controlled. Anorexia can lead to previously placid people becoming panicked and violent, particularly when faced with the prospect of eating.
11 Decreased Sociability
As time went on the men in the MSE became less sociable, spending more and more time alone. Many people with anorexia cut themselves off from family and friends as their eating disorder takes over every aspect of their lives and becomes the only thing that matters. Humor, enthusiasm, and sociability progressively reappeared with re-nourishment.
12 Self-Centred
The men also became self-centred, becoming less interested in others and only thinking of themselves. This can also be true in anorexia. Desperate pleas from friends and family fall on deaf ears as the person with the disorder is unable to see outside of their own situation and the smallness of the world that the illness creates.
13 Hoarding
The men made out-of-character purchases like old books, second-hand clothes they didn’t need and other ‘junk’. They were puzzled by this behaviour. Several subjects insisted that they had grown unusually anxious to save money for a “rainy day”. Hoarding is normal in a famine; it’s also common in anorexia.
14 Loss of Sex Drive
Sexual feelings declined during the semi-starvation phase of the MSE until they were entirely absent in all but a few men. They stopped dating, and after 12 weeks’ rehab these feelings were still low. By week 33 of rehab the men’s sex drive had returned to normal. Again, many with anorexia become disinterested in sexual or romantic relationships during the course of the illness.
15 Anxiety and Neurosis
The men developed excessive anxiety as they starved. Keys notes that in semi-starvation the striking feature is the general elevation of the “neurotic” end of the profile. It’s often suggested that people who are prone to anxiety are more likely to develop anorexia nervosa. This may be true. It’s certainly true that the eating disorder can increase anxiety, particularly around eating, which becomes inordinately stressful.
16 Compulsions
Keys states that there was an increase in the men’s scores for compulsions during the experiment, although this isn’t expanded upon in detail. Many people with anorexia exhibit compulsions, particularly exercise and movement compulsions but also, anecdotally, behaviours like skin picking.
17 Stealing
One man, who became particularly disturbed, stole trinkets. Another with an extreme gum-chewing habit stole gum when his finances couldn’t sustain it. Another stole a student’s lunch. While this is certainly not universal, I have read accounts of people with anorexia shoplifting, usually for inexpensive items or food.
18 Suicidal Ideation
At least one man in the MSE talked of feeling suicidal. Sadly the rates of suicide or attempted suicide in anorexia nervosa are high.
19 Hypomania
The same man presented the picture of a hypo manic: he was overly talkative, emotionally unstable, and somewhat elated. I don’t know of any research on this but I recognise the overly talkative, emotionally unstable part of this as a description of my daughter, particularly in the early years of anorexia.
20 Restlessness
The same subject who stole gum is described as developing a restlessness, particularly during the last six weeks of semi-starvation. This fits with the compulsive movement element that many with anorexia have and that was written about historically by William Gull and others.
21 Indecisiveness
This same man had a characteristic indecisiveness which was markedly aggravated during semi-starvation. An inability to make decisions was one of the first things I noticed in both of my daughters after the onset of anorexia.
22 Eating From Rubbish Bins
He also developed a compulsive attraction to refuse and a strong, almost impelling, desire to root in garbage cans… he actually ate garbage, a sandwich he found… on the ground. I have read about some with anorexia or bulimia fishing food out of rubbish bins. I’m not sure how common this is, but it’s certainly the experience of some.
23 Self-Harm
One man attempted to mutilate himself on two separate occasions, the second time succeeding in chopping off three fingers on his left hand. Keys is clear: this was not an accident. Again self-harm is relatively common in people with anorexia. Surprisingly, this man remained in the experiment.
24 Breaking the Rules by Eating Minuscule Amounts
One striking thing about the MSE was the men’s adherence to the rules, despite their immense biological need for proper sustenance. Inevitably, sometimes the rules were broken though. But Keys notes that when rule breaking occured, it was often in a pitiful way, using an inefficient and neurotic approach to the solution of the problem of hunger: the men ate garbage, raw swede or infinitesimal amounts of food. And guilt was a looming presence.
25 Making Bizarre Bargains Because of the Rules
Fear of starvation leads to starvation. This is true in anorexia for some and, it seems, in ‘normal’ starvation. Keys talks about this strange behaviour in a number of the men in the MSE: Some of them attempted to lose weight in order to obtain increased bread rations… or to avoid reduction in rations. These men tried to become thinner in order to be allowed to eat more or the same amount of food. This is highly reminiscent of the bizarre bargaining that people with anorexia will do. The difference is that the rules of anorexia are internal when the rules of the MSE were external.
26 Guilt After Eating
Keys talks about the MSE subjects’ guilt if they broke the rules by eating when they shouldn’t. Guilt around eating is an enormous part of anorexia.
27 Bulimic-Type Behaviour
The man who stole gum also developed bulimic-like behaviour after being released from the experiment at the end of the starvation period. He developed a cycle of eating vast amounts of food and then being sick, which lasted for several weeks but eventually subsided. In the rehabilitation phase, several other men had spells of nausea and vomiting. Another man suffered a sudden ‘complete loss of willpower’ while working in a grocery store. He ate a large amount of cookies and two bananas. He was immediately upset emotionally, with nausea, and vomited.
28 Hunger High
It’s often said, not least by me, that people who do not have a predisposition to anorexia nervosa do not experience a high from energy deficit. I was, then, intrigued to read this: feeling ‘high’ was sometimes attributed by the men to a ‘quickening’ effect of starvation or to success in adjusting to the semi-starvation diet. The high, Keys notes, was inevitably followed by a low. So perhaps starvation can induce a high in people other than those with a predisposition to anorexia after all. The second part of the sentence is particularly reminiscent of reports I’ve read of this phenomenon in anorexia — where people feel a sense of achievement from not eating, even a sense of power.
It’s important that people with anorexia nervosa or other restrictive eating disorders are aware that many of the psychological aspects of these disorders are simply the result of starvation. This seems to be rarely emphasised in treatment. I believe this knowledge could have a highly motivating effect on some to get better.
I particularly think that we need to recognise the months it takes for the brain to recover from malnutrition. At present, there’s far too much systemic expectation that a small amount of weight gain and a bit of therapy will do the job. It won’t. If it took some of the men in the MSE more than five months of proper, sustained re-nourishment to get over their food obsession, why would we expect this to disappear in someone with anorexia after minimal weight gain and ten weeks of cognitive behavioural therapy (CBT)?
There are, of course, important psychological features of anorexia nervosa that weren’t present in this study and perhaps can’t be explained as the normal effects of starvation: the anorexic voice; the upside-down messaging around food, exercise and body size; movement and exercise compulsions (although other compulsions and restlessness are mentioned). However, it’s worth noting that all the subjects of the MSE were men. Of course, men and boys get anorexia too, perhaps in far larger numbers than we know, but I wonder what the psychological findings of the MSE would have been had Keys studied semi-starvation in women. Also, just because these effects weren’t seen in the men in the MSE, it doesn’t follow that they are not the result of restriction in someone with a slightly different biological make-up, and that they won’t be reversed with substantial weight gain and time.
Whatever the differences, the clear parallels between the psychological effects of the MSE and anorexia nervosa highlight that our bodies are sometimes very much in charge of our brains, particularly in times of physical strain. As Ancel Keys puts it, the:
… bond between the physiological status of the organism and the “psyche” is closer than is sometimes realized. The dominance of the “body” becomes prominent under severe physical stress.
I would recommend this book to anyone researching eating disorders, working with people with eating disorders or with a lay interest, like me. It’s fascinating, thorough and presented in a thoughtful manner. When I embarked on reading it, it was a bit of a challenge to myself. I didn’t expect to enjoy it — after all who wants to read about something as horrible as hunger — but I found myself easily engaged and constantly surprised, particularly by the revelations of volume II.
The Biology of Human Starvation gives us great insight into the human condition of starvation. And although Keys exhibits a distinct lack of understanding of anorexia nervosa, his work remains an invaluable tool in modern endeavours to decipher this illness.