Mr. L., as well as the writer, continued in good health and in fairly good spirit throughout the starvation period. On the fourth and fifth days both men felt somewhat weak. Some mental depression was also experienced, especially on the fifth day, by Mr. L., who complained of feeling dizzy on getting on his feet after lying down. An hour's lecturing seemed quite an effort on the fourth starvation day, and on the fifth day both men felt distinctly better when lying down than when sitting or standing. Both slept fairly well during the four nights of the starvation period, despite the persistent hunger contractions and the unusual surroundings of the research laboratory as a sleeping-room. The secretion of urine was diminished, although water was taken whenever desired. In some cases a glass of water was taken to diminish the hunger pangs. The writer did not enjoy a cigar after the second day; in fact, smoking tended to produce nausea. This is an indication of increased excitability of the nerves of the gastero-intestinal canal.
During the period of control observations both subjects trained themselves in judging the relative intensity of the individual hunger pangs, and in this both of them attained a fair degree of efficiency. They can invariably tell the onset of a hunger period before the contractions have reached a sufficient intensity to be recognized as individual hunger pangs. This initiation of the hunger period consists in a gradually increasing tonus and feeble and more or less rhythmical contractions, and this is felt as a continuous mild hunger or a moderately steady and somewhat uncomfortable tension in the epigastric region. This sensation is not dependent on or influenced by the distended balloon in the stomach cavity. In .this way one can usually manage to record practically every hunger period during the day, simply by starting observations as soon as one feels the very onset of the hunger period. The periods of strongest hunger contractions, or the hunger tetanus, are also felt as continuous and .intense hunger. And there is a characteristic relief from the diminished tension within a minute or so after the period of hunger contractions is at an end.
During the first two or three days the hunger sensations seemed both to Mr. L. and the writer somewhat more severe than any hunger experienced during the control period, in fact, more severe than seemed warranted from the degree of intensity of the gastric contractions. To be sure, the hunger contractions of the stomach were usually somewhat stronger than, and in every case at least as strong as, during the control period, but the hunger sensations seemed even stronger proportionately. During the fourth and the fifth hunger days, on the other hand, the hunger sensation seemed somewhat weaker than one could have predicted from the intensity of the hunger contractions. In fact, the sensation did not even seem to be as keen as that produced by a period of strong hunger contractions 6 to 10 hours after the previous meal. The reader will recall that the gastric hunger contractions on the last two days were of normal or greater than normal intensity.
The sensation of hunger was almost continuous after the first day of starvation. That is to say, the hunger sensation referred to the epigastrium did not wholly disappear during the intervals between the vigorous gastric contractions. This feeble but continuous hunger sensation is evidently caused by the increased gastric tonus and more or less continuous but feeble rhythmical contractions that represent the periods of quiescence of the empty stomach during prolonged starvation. On the fifth day of starvation the continuous hunger sensation seemed to be tinged with a peculiar "burning"* sensation, also referred to the stomach, the fusion resembling somewhat the feeling of "sick stomach"' with its attendant central depression. This "burning'* sensation was probably caused by acid stimulation of hyperexcitable nerve-endings in the gastric mucosa.
The appetite during the starvation period ran practically parallel with the sensation of hunger. It was distinctly increased during the first two or three days, and diminished on the fourth and fifth days. In fact, the depression of appetite on these two days seemed distinctly greater than the depression of the hunger sensation. Instead of an eagerness for food, there was almost an indifference toward food, despite the persistent hunger call of the empty stomach. This was particularly true of Mr. L. He stated several times on the fourth and fifth days that the sight of food led, not to a feeling of eagerness for eating, but to a feeling partaking of the nature of revulsion or nausea. This was not experienced by the writer. Food looked good to him throughout the starvation period, but he found it much easier to dismiss thoughts of food and eating from his mind toward the end than at the beginning of the period.
The reasons for this seeming discrepancy in the parallel between the intensity of gastric hunger contractions and the intensity of the subjective hunger sensation during the five days* hunger period can only be conjectured, at present. We are inclined to believe with Stohr that the weakening of the hunger and the appetite sensations toward the end of the period is due to a depression of the central nervous system. This central depression, however caused, was clearly in evidence both in Mr. L. and the writer. Afferent impulses from the viscera, differing from the normal quantitatively, probably also play a part in the situation.
More prolonged starvation in man appears to lead at times to a heightened or abnormal cerebral activity, as shown by the feeling of exaltation, visual and auditory hallucinations, etc. These phenomena are probably determined quite as much by the type of emotional processes of the individual as by the effects of starvation, since they are reported more frequently by religious ascetics, than by worldly minded men starving for purposes of science or health. The hallucinations may be due to depression of certain cerebral centers, and hence similar to dreaming rather than to actual increase in cerebral excitability. In any case, these phenomena are probably due to starvation changes in the blood and the brain tissues, rather than to the gastric hunger mechanism.
Both in Mr. L. and the writer practically all of the mental depression and some of the feeling of weakness disappeared during the partaking of the first meal after the fasting period. This central depression is therefore essentially a reflex condition depending probably on afferent impulses from the digestive tract, rather than a result of lack of nutrient material in the blood. But complete recovery from the bodily weakness did not take place until the second or third day after breaking the fast.
From the second day on both men felt unusually well, distinctly better, in fact, than before the hunger period, although both men are normally in good health and vigor and not hampered by excessive fat. The writer felt as if he had had a month's vacation in the mountains. The mind was unusually clear and a larger amount of mental and physical work was accomplished without fatigue. In the writer's own case, the five days* starvation period increased the vigor of the gastric hunger contractions to that of a young man of twenty or twenty-five, and the empty stomach retained this increased vigor for at least three weeks after the hunger period, when observations were discontinued owing to absence from the University. This improvement or rejuvenation of the stomach is not a matter of subjective feeling of opinion, but a matter of objective record on the tracings. Neither Mr. L. nor the writer can be considered as ordinarily eating to excess, although the daily intake of protein and calories is greater than the minimum requirement advocated by Chittenden. The cause of the improvement was not loss of excessive adipose tissue.
Mr. L. states that the augmentation of hunger and appetite persisted for at least two or three weeks after the end of the starvation period.
We are familiar with but not particularly impressed by the arguments of enthusiasts who advocate starvation as a panacea for various human ills. But this personal experience leads us to suspect that there is more value in some of these measures than is ordinarily considered. Civilized man has traveled far from the conditions of life among wild animals and primitive man, with whom periods of starvation are not uncommon. Occasional periods of starvation, say once or twice a year, in the case of healthy adult persons may not only add to the joy of living but also to the length of life. There is some evidence resulting from experiments with animals that periods of starvation may accelerate growth and improve the general body metabolism (Deland, McCollum, Howe, Morgulis).
During the entire starvation period the hunger sensation was strong enough to cause some discomfort, but not to a degree that could be called marked pain or suffering. This discomfort was at no time sufficient to interfere seriously with work. And since practically all observers agree that the hunger discomfort is greatest during the first few days of starvation, it seems probable that our five days of starvation gave us a taste of the maximum discomfort that would be experienced in more protracted fasts. Accounts of acute sufferings from mere starvation (water being at all times available) must therefore be wholly imaginary, or the result of fear and panic. Voluntary starvation is in no sense a heroic act, and citation of hunger experiments on animals in the interest of science as instances of cruelty to animals is without foundation.