This section is from the book "The Hygienic System: Fasting And Sun Bathing", by Herbert M. Shelton. Also available from Amazon: The Hygienic System Vol III Fasting and Sun Bathing.
Organisms capitalize the results of the joint work of their several organs and physiological systems in the form of capacities and valuable stored substances. They may learn to use this stored capital, this biological raw material which they have woven into their fabric and built into their flesh and blood, in the interest of the whole organism, or in doing useful work; or, they may consume it in wasteful expenditures of one kind or another, or they may use it under circumstances, such as "disease" or famine, when food cannot be digested or is not to be had.
In Persia, there exists a variety of sheep called fat-tailed sheep, that has an enormous tail made up of fat and other stored food elements. During seasons of plenty the sheep stores up large quantities of food in its tail--prize specimens often developing such heavy tails that their owners provide them with small carts which are placed under the tails and fastened to prevent the tails from dragging the ground. When pasturage becomes scarce the sheep draw upon the food reserves stored in their tails for nutriment. This is a literal example of "cutting off the tail of a hungry dog and feeding it to him."
The tail of the Gila Monster, a poisonous reptile (lizard) of the American Southwest and Mexico, serves as a storehouse of reserve food. A well-fed Monster possesses a thick, heavy tail. In barren years the Monster may be found with its tail thinned down almost to the spine. Like the big-tailed sheep of Persia, the Monster stores food in its tail when food is plentiful and subsists off its tail when food is scarce. They are capable of going for long periods without food, having been kept in cages without food for upwards of six weeks.
Fasting female birds and fish will absorb the eggs stored in their bodies and utilize these as food. Morgulis, experimenting with the newt, Duemyctium, found that the "ripe" female withstands starvation best, because she actually absorbs and utilizes the large reserve of stored food in the mature eggs and thereby saves her other organs and tissues from wasting. Heidkamp found, in experiments with Tritoncristatus, a fresh water salmon, that when the female is denied food the fully developed eggs in her body are the first to be absorbed.
These specialized provisions for storing food reserves are analogous to the provision possessed by the camel for storing water. There are other animals which have other specialized storages for food reserves upon which they may draw in times of food scarcity. Although such specialized structures are not universal in the animal kingdom, nature provides in all animals for the storing of food reserves, even though there is no specialized structure provided for this purpose; for food is as likely to be scarce for one animal as for another. All hibernating animals are equipped with specialized apparatus for storing up food reserves. It has been urged against fasting by man that he is not a hibernating animal. It is quite true that man possesses no specialized food reserves, as does the Russian bear, for example; but he does possess generalized food reserves, like all animals. The dog, cat, cow, horse, elephant, etc., are not hibernating animals, yet all of these instinctively refuse food when ill or wounded. Hibernating animals are inactive and have stored food reserves which have been put away for just this period; but there are other animals which go for long periods of time without food and which are vigorously active at the same time. The Alaskan fur-seal bull and the salmon are remarkable examples of this. The fact is that, all animals, man included, are provided with food reserves which are held in store against a period of forced or necessary abstinence from food.
There is an economical tendency of the organism to accumulate reserve stores in the body so that under stress or strain or deprivation and want, it shall be able to go on for sometime without the ordinary supplies of food. Man or animal in case of famine, shipwreck, or under other circumstances in which food cannot be secured, would perish forthwith, except for these generalized food reserves stored in the body.
We saw in a previous chapter that each cell and each organ has its own private food reserve. In addition to this there is a considerable quantity of glycogen stored in the liver, much surplus protein and other food substances carried in the blood and lymph, several pounds of fat in the body (even thin people have considerable fat) and much food reserve in the marrow of the bones. In the glands there is stored a considerable supply of vitamins. It is possible that the body can retain and re-use its vitamins as it can its iron and certain other minerals. Collectively, the above stores constitute a reserve food store that is capable of sustaining the vital organs and their functions through an emergency of considerable length.
The ensemble of the body's food reserves is well balanced with respect to the various nutritive elements, salts, vitamins, etc. They are capable of meeting the nutritive needs of the vital tissues for long periods.
There is still another source of foods, which, in some animals may amount to several days' supply. In ruminants the food residues (undigested food) in the intestinal tract are usually very large (so large, indeed, that the variability in "fill" contained in the digestive canal disguises the true body weight and has been a constant cause of uncertainty in determining changes in the body tissues, and amounting often in the case of the steer to one-fifth of the entire body weight) and serve as a source of food for a considerable period after food has been withdrawn, so that the immediate demands upon the body's actual reserves are not great.
The reserves of omnivorous animals, although usually plentiful, are quickly exhausted when food is denied. In dogs and man the alvine canal is almost immediately exhausted of its food supply, so that the true fasting period is more quickly reached. The whole expense of fasting is thrown upon the food reserves in their bodies almost from the outset.
Hibernation differs from ordinary fasting in that the hibernating animal possesses special stores for the period, and in that the metabolic rate is decreased much more in hibernation, thus lessening the need for food.
The fasting organism subsists on materials previously stored in its tissues. It would be erroneous to suppose that during a fast, under whatever condition, the processes of nutrition are suspended. Only those concerned with the digestion and absorption of raw materials are interrupted.
The fasting organism is nourished as truly off its accumulated reserves as if it daily consumed an abundance from the fat of the land. Prof. Morgulis says, indeed, that "inanition must be regarded as a special--perhaps, the simplest,--form of nutrition." He adds that materials for growth and repair of tissue, energy for maintenance and energy for work, are supplied "under the conditions of inanition" from the "rich deposit of nutritive substances" which "every organism contains in its tissues" and "which constitute the common foods when they serve to nourish another organism."