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.
Major W. C. Gotschall, M. S., says: "There is nothing new about fasting. Among the ancients it was recognized as a sovereign method of attaining and maintaining marked mental and physical efficiency. Socrates and Plato, two of the greatest of the Greek philosophers and teachers, fasted regularly for a period of ten days at a time. Pythagoras, another of the Greek philosophers, was also a regular faster, and before he took an examination at the University of Alexandria, fasted for forty days. He required his pupils to fast for forty days before they could enter his class." H. B. Cushman tells us in his History of the Choctaw, Chickasaw and Natchez Indians, that the Choctaw warrior and hunter "often indulged in protracted fasts" to train him to "endure hunger."