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.
The vital cells of the body must be nourished during the fast. These are nourished off the food reserves stored in the body and off the less essential tissues, or off the salvable portions of the "diseased" and dead tissues. The body possesses power to refine and use the materials it has on hand during a fast of reasonable length. The popular belief that immediately upon the discontinuance of meals the blood and solid structures of the body begin to break down and that organic destruction sets in, is unfounded as is proved by the results obtained in many thousands of cases of fasting patients. The vital cells of the organs and glands of the body, those cells doing the actual physical and chemical work of these organs, do not begin to disintegrate until actual starvation sets in. We know that it is not until the total of the body's reserves has been consumed that death from starvation sets in and it is only after these are consumed that nature will permit a single vital organ to be damaged. Under favorable conditions of rest and warmth these reserve stores may hold out for weeks and even months.
The faster lives on the same thing when fasting as when eating, the difference being that when eating, he replenishes his nutritive stores each day, while, in fasting he gradually consumes them. The faster lives on those portions of his body which represent stored food and not upon the vital or functioning tissues of his body. The vital cells are not injured unless the fast is prolonged beyond the point where all the body's nutritive reserves are consumed and no fasting advocate believes in or practices such a thing.
The fasting body begins to grow smaller, and in order to maintain the integrity of its vital organs, it utilizes all the surplus material it has on hand. Growths, deposits, effusions, dropsical swellings, infiltrations, fat, etc., are absorbed and used to support these organs. With no digestive drudgery on hand, nature employs the long desired leisure for general house cleaning purposes. Accumulations of surplus tissues are overhauled and analyzed; the available component parts are turned over to the department of nutrition, while the refuse is thoroughly and permanently removed.
Emaciation frees the body of excess inert materials in its tissues and proves thereby to be a great boon. One of the first things that nature does in an acute "disease" is to cast off a lot of her surplus weight. She dispenses with the unnecessary burden. The lowering of weight is a natural method of defense. It represents a reduction of the body's nutritive labors, so that these may be fulfilled without exhausting the visceral organs.
There is no known measure that is equal to fasting as a means of accelerating the processes of elimination. When food is withheld, only a short time elapses before the organs of elimination increase their work of throwing off accumulated waste products. Secretions begin a physiological house cleaning.
Carrington and others insist that in fasting accumulated waste and toxins are eliminated first and until these are eliminated none of the really valuable tissues of the body will be destroyed. This is to say, excess food materials in the body and diseased tissues are utilized first in the fast. Carrington, indeed, thinks that "the whole physiology of the fast is contained in" this principle. He says that "weakness is due, not to lack of food, but to the poisons of the disease; emaciation is due not to the fact that too little food is supplied the system, but to the fact that disease wastes the body--by poisoning it."
The nervous system of the faster becomes relatively larger than at other times and its sensibilities become more acute. For this reason, the actions of the body in relation to drugs are more prompt and vigorous when fasting than when feeding. Because this is so, fasting usually compels one to discontinue one's drug habits. This will be discussed more fully in a later chapter. The faster should avoid drugs of all kinds.