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.
Luke mentions in his Gospel the practice of fasting one day out of each week, which seems to have been very general in his day. Periodic fasting has been practiced by many different peoples and by many different individuals. It is asserted that the ancient Egyptians were accustomed to fasting for a brief period, about two weeks each summer. Many people of today do this same thing. They have a fast or two fasts each year. Others follow the custom referred to by Luke and fast one day out of each week. Others fast three to five days out of each month. The practice of periodic fasting takes many forms with many different individuals. These fasts are usually of but short duration, but they are always of distinct benefit.