I guess I am into reading turn of the century books about fasting.

Upton Sinclair, author of The Jungle (and around 100 other books), performed many dietetic experiments on himself, including being a raw-food vegan for 3 years (Although he liked how he felt and how little time it took to prepare meals, he stopped when it wasn't giving him the energy he needed to write for 18 hours a day). This book is a compilation of articles that he published about his experiences with fasting and many letters from readers about their own fasts. It does appear that fasting ~2 weeks can be the cure for many dietary related illnesses and maladies, and can push the reset button on poor eating habits. Contemporary stories that I've heard agree.