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.
Fasting above all other measures can lay claim to being a strictly natural method. There can be no doubt that it is the oldest of all measures of meeting those crises in the organism called "disease." It is much older than the human race itself since it is resorted to instinctively by sick and wounded animals.
"The fasting-cure instinct," says Oswald, "is not limited to our dumb fellow-creatures. It is common experience that pain, fevers, gastric congestions, and even mental afflictions 'take away the appetite,' and only unwise nurses will try to thwart the purpose of nature in this respect."
The doctrine of total depravity taught men to distrust the promptings of their natural instincts, and while the doctrine is slowly fading from religion, it is as strong as ever in medicine. The promptings of instinct are ignored and the sick are stuffed with "good nourishing food" to "keep up their strength."
"There is a very general concurrence of opinion," says Jennings, "that the aversion to food that characterizes all cases of acute disease, which is fully in proportion to the severity of the symptoms, is one of Nature's blunders that require the intervention of art, and hence enforced feeding regardless of aversion." Dr. Shew declared: "Abstinence is by far too much feared in the treatment of disease generally. We have good reason for believing that many a life has been destroyed by the indiscriminate feeding which is so often practiced among the sick."
In the human realm, instinct prevails only to the extent that we permit. Although one of the first things Nature does to the person with acute "disease" is to stop all desire for food, the well-meaning friends of the sick man encourage him to eat. These may bring in tasty and tempting dishes designed to please his taste and excite an appetite but the most they ever succeed in doing is to get the patient to nibble a few bites. The ignorant physician may insist that he must "eat to keep up strength," but Mother Nature, who is wiser than any doctor who ever lived, continues to say, "do not eat."
The man who is sick, but who is able to be about his work, complains of having lost his appetite. He no longer enjoys his food. This is because his organic instincts know that to eat in the usual way is to increase the "disease." The man thinks the loss of appetite is a great calamity and seeks a way to restore it. In this he is encouraged by physician and friends, who, alike, erroneously think that the sick man must eat to keep up his strength. The doctor prescribes a tonic and stuffing and, of course, the patient is made worse.