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.
A classical example of the way in which fasting permits the stomach to rejuvenate itself is that of Dr. Tanner. He suffered for years with dyspepsia before his first fast. Indeed, it was this suffering that followed every meal that caused him to refrain from eating in order to miss the distress. So remarkably did his stomach repair itself during its period of rest that he was able, very foolishly, of course, to eat "sufficient food in the first twenty-four hours after breaking the fast to gain nine pounds, and thirty-six pounds in eight days, all that I had lost." Although this was a rash procedure, the doctor suffered no apparent ill consequences from it. We cannot approve of such eating following a fast, but cite his example to show what a formerly weakened and dyspeptic stomach can do after a period of fasting.
A stomach rejuvenated through rest returns spontaneously to the normal performance of its function. A weak and dyspeptic stomach resumes normal function after a fast. This alone is sufficient to prove the strengthening results of a rest for the stomach. Both its muscles and its glands are rejuvenated by a period of rest.
It is often objected that fasting permits the stomach to collapse and that it so weakens the stomach that it will no longer be able to digest food. Most stomachs are so weakened by the overwork that results from our national habit of over-eating that the rest that fasting affords it is just what the stomach needs most.
Fasting provides a rest for the stomach, thus giving it an opportunity to repair itself. Morbid sensibilities are overcome, digestion is improved, a distended and prolapsed stomach shrinks and tends to resume its normal size, ulcers heal, inflammation subsides, gastric catarrh is eliminated and the appetite tends to become normal.