Fasting and Eating for Health : A Medical Doctor's Program for Conquering Disease
by Joel Fuhrman
Griffin Trade Paperback; (April 15, 1998) ISBN: 031218719X
"Crisis periods can occur during fasting. The best book I know and trust about fasting is by Dr. Joel Fuhrman. Fasting is safe for most people, but for a small minority can be harmful (or deadly). Be sure to read his book, since he is a licensed medical doctor and has conducted supervised medical fasting clinics professionally for many, many years."