Since water fasting is the most intense of the fasting methods, it's important to learn as much as you can before beginning one. The two authors below have supervised the water fasts of thousands of individuals. Their familiarity with the process is unparalleled.
And if you're serious about trying a long-term therapeutic water fast, this should be considered "required reading".
First and foremost, read Dr. Joel Fuhrman's book Fasting and Eating for Health: A Medical Doctor's Program for Conquering Disease, published in 1995.
It covers a broad array of modern diseases and how water fasting and/or nutritional therapy can improve or even heal those conditions. There are whole chapters on diabetes, heart disease, autoimmune diseases, and obesity. There's a chapter on headaches/migraines and hypoglycemia, covered together because of their close symptomatic relationship. If you have any of these conditions, you MUST read this book!
Fuhrman's book cites current research and studies, not to mention, draws on his years of experience at supervising fasts for thousands of individuals. Because he is an MD, his approach to the subject is thorough and cautious, explaining the science of why and how the body does what it does. I recommend reading his book so you have all the facts, so you gain a scientific understanding of the process as a whole.
Dr. Fuhrman's approach makes it clear that we cannot discuss fasting as medical therapy without balancing it with what to do when not fasting--in other words, what to eat, or nutritional therapy. His newer book, Eat to Live, expands on his ideas about nutritional therapy and is directed mostly at those wishing to lose weight, but see green box below.
Fasting and Eating for Health is highly referenced and researched. You will get a good education from reading it.
Considered a classic on the subject of fasting, Herbert Shelton's book, Fasting Can Save Your Life is packed with a lot of information.
Shelton (1895-1985) was a pioneer in fasting in the modern Western world. He ran a fasting retreat in Texas and wrote several books and articles on Natural Hygiene--a comprehensive health care system based on ideas dating back as far as the 1830s.
These "ideas" were radical for the 1800s. They made the assertion that health is a product of lifestyle and environment. That sunshine, clean air and water, a quality diet of fresh vegetables, fruits, nuts, grains and seeds, make for a healthy individual. Also necessary are sufficient rest and exercise, emotional poise, and self esteem.
Not such radical ideas anymore. We now know the truth of those assertions.
As important as the therapy of water fasting was to Shelton, he did not advocate it as an isolated therapy but as a part of his overall system of Natural Hygiene. The patient was taught how to make healthier life choices.
Even though the last edition of this book was copyrighted 1978, this work is far from irrelevant. One can't overlook the level of experience Shelton had gained from supervising fasts. He claimed to have conducted over 25,000 fasts (some places say 40,000) in 30 years. No one else can rival that amount of experience in the study of fasting for the purpose of healing disease.
But it is true that some information in this book should be taken with an understanding of the context in which it is given. Medical knowledge of the human body is far greater today than in 1978. And, in my opinion, his cautions seem weak, as there clearly can be complications during a fast, but then, I must remind myself, he never recommends water fasting without professional supervision by those trained in the process.
Some feel it is an outdated notion to not give enemas to those fasting, which is what Shelton advises, but here is where Dr. Fuhrman's experience and medical expertise can help. In his more recent experience with supervising fasts, he confirms that enemas are not necessary, that toxins are not reabsorbed into the system, that it is fine to let the colon "take care of itself".
Fasting Can Save Your Life is a very inspiring read that is full of case study after case study. Shelton had a lot of cases from which to draw--as many as 40,000! All cases demonstrating the body's ability to heal itself. After reading this book, you will be motivated to begin a water fast.
Reading both of these books would be ideal, but if you only time to read one, read Fuhrman's. His more modern approach and terminology would be the most helpful to those preparing for water fasting.