Now hunger and [Erysichthon's] belly’s deep abyss exhausted his ancestral wealth, but still hunger was unexhausted and the flame of greed blazed unappeased . . . When his wicked frenzy had consumed all sustenance and for the dire disease provision failed, the ill-starred wretch began to gnaw himself, and dwindled bite by bite as his own flesh supplied his appetite.
~~ Ovid, The Metamorphoses
Examining hunger and starvation in individuals is not an easy task, for without body measurements, food-recall questionnaires, blood tests, or any of the other standard tools used by nutritionists to measure nutritional status, accuracy may be fleeting. But if we lack a sure-fire understanding of what happens in individuals, examining the impact of hunger and starvation on populations — in this case, historically — proves to be even more problematical.
But we need to begin with the individual, for a number of reasons.
According to a 1940s classic study of human starvation performed by Ancel Keys at the University of Minnesota, food deprivation impacts greatly on human behavior and goes far beyond the usual marker of weight loss.
How does starvation differ from hunger?
Starvation is the lengthy and continuous deprivation of food, a condition in which the absence of food forces the body to feed on itself. Causes of starvation include famine or other food shortages, war, fasting, systemic illness, social and religious beliefs, or abnormalities of the mucosal lining of the digestive system.
Hunger can be loosely defined as “‘not enough food’ to satisfy body needs. It results in ravenous hunger, eating nearly anything available and lots of it. Eventually, the body adjusts, but the appetite doesn’t.” Causes of hunger include those given for starvation, but more often than the etiology of hunger tends to be economic.
The Romans knew hunger and made it a goddess, Fames, diametrically opposed to Ceres (Demeter). Ovid describes her in The Metamorphoses 8. 791 ff:
… set out in search of Fames (Hunger) and found her in a stubborn stony field, grubbing with nails and teeth the scanty weeds. Her hair was coarse, her face sallow, her eyes sunken; her lips crusted and white; her throat scaly with scurf. Her parchment skin revealed the bowels within; beneath her hollow loins jutted her withered hips; her sagging breasts seemed hardly fastened to her ribs; her stomach only a void; her joints wasted and huge, her knees like balls, her ankles grossly swollen.
No matter where in the world — or when in history — the human body needs at least two things in order to survive, to prevent and surmount starvation. Those two things are adequate nutrient intake—protein, vitamins, minerals—and sufficient energy to spare the protein in the diet and to make sure that the brain, which uses only glucose, is well supplied without metabolizing any protein intake. [Without enough calories in the diet, the body begins to catabolize — or break down — muscle mass into the energy necessary for the body to function. If enough calories exist in the diet, this breaking down of protein does not occur.]
In the 1940s, when Dr. Ancel Keys studied the effects of starvation on 36 young men, all completely healthy both mentally and physically, he worked with subjects registered as conscientious objectors during World War II, providing them with a diet very low in calories.* The objective was to determine what impact the food conditions in wartime Europe had on the people there. It is unlikely that any such study could ethically be carried out today, because of restrictions on the use of human subjects in medical research. For that reason, Keys’s study is all the more important. The Keys study allows scientists and others to learn about starvation in a controlled situation, rather than by extrapolating data from the so-called “natural” starvation that results during conditions of famine and war. And since the mental health of Keys’s potential subjects was also tested via standard tools, with only the most mentally stable men allowed into the study, psychological testing eliminated the potential variable of pre-existing mental illness.
Exactly what happens physiologically in starvation, other than the expected weight loss?
First to be lost are fat deposits and large quantities of water. The liver, spleen, and muscle tissue then sustain the greatest loss of weight. The heart and brain show little loss proportionately. The starving person becomes weak and lethargic. Body temperature, pulse rate, blood pressure, and basal metabolism continue to fall as starvation progresses, and death eventually ensues, unless feeding resumes.
Essentially a starving person moves from what medical jargon terms “positive nitrogen balance” to “negative nitrogen balance.” In other words, the body begins to catabolize, or break down, protein in the muscles, as mentioned above.
Then, as the body seeks an energy source for the nervous system, primarily the brain, the body begins to burn fat. Although body fat cannot be broken down to glucose and thus provide a source of “food” for the brain, by breaking down fatty acids, which make up body fat, the body can, however, convert glycerol (with its three carbons) to glucose. But this is a very insufficient and inefficient source of energy. A starving person then goes into ketosis, which essentially means that an excessive amount of ketone bodies are circulating in the blood and present in the urine. Negative aspects of long-term ketosis include kidney damage, among others. (Ketone bodies result from the breakdown of fats.) This scenario accounts for the continuing craze for low-carbohydrate diets; people go into ketosis, after losing a large amount of weight at the beginning — chiefly water weight and lean tissue mass, which is rapidly regained when re-feeding occurs, as Keys discovered in the post-starvation part his study.
In the beginning, some of the typical physical symptoms of the starving subjects in Keys’s study included fatigue, muscle soreness, and hunger pangs. Then the following symptoms appeared with regularity: gastrointestinal discomfort, dizziness, decreased need for sleep, hypersensitivity to light and noise, headaches, fainting, hair loss, poor motor control/clumsiness, decreased cold tolerance, visual disturbances (inability to focus, eye aches, “spots before the eyes”), auditory disturbances, and paresthesia or tingling in the hands and feet. According to Keys, one of the most noticeable symptoms turned out to be extreme emaciation in the face. Keys emphasized that these symptoms illustrate the extremes to which the body will go to preserve and produce energy for the brain’s continued functioning.
Thus even though Keys’s work took place over 60 years ago, his research still offers insights into the impact of constant caloric deprivation on individuals, populations, and, most interesting of all, on how the food deprivation of those individuals and populations may have in turn affected historical events and trends.
To be continued …
© 2009 C. Bertelsen