In theory a healthy person can fast for 40 days without irreparable damage to his/her health. In reality very few individuals can last even half that long because their bodies are so toxic. Even back in the early days of the twentieth century fasting expert Arnold Ehert wrote that 50-60% of healthy men and 80-90% of the chronic sick would die from their latent diseases if they submitted to a long fast. Paul Bragg reiterated those words 50 years later. A forty day fast is far too long for anyone to attempt without close medical supervision.

So many people seem to think that fasting is simply not eating for a certain period of time. Nothing could be further from the truth. Genuine fasting is like knifeless surgery. Its purpose is not rapid weight loss, but rather intense detoxification. Weight loss is an expected and usually anticipated result of fasting, but should not be the primary goal since fasting weight loss is rarely permanent. Just like surgery done "under the knife", a fast must begin with careful preparation. Weeks, even months of a cleansing diet is required for any fast lasting more than 3-5 days. The onslaught of released toxins is too strong for the average person to handle unless some prior cleansing has come first. Also the cleansing and detoxification will come in waves during a long fast. It is not a one-time cleansing crisis, it is a series of crisis as the body goes into ever deepening levels of detox.

Water only fasting needs to be done with near total bed rest. The longer the fast, the more vital this rest becomes. People fasting for more than 10 days also need frequent blood tests to check the level of vital minerals in their system. For example too little sodium and potassium can lead to rapid heart failure and death. (I've been in that spot, I was already in the early stages of heart failure when I fainted and was rushed to the hospital). Fluid intake and output also need to be monitored. Taking too much or too little water can prove very dangerous to the fasting body, this must be monitored on an individual basis, there is no "one size fits all" answer to water intake.

The best way to begin fasting is to fast one day a week for 36 hours for at least a month. Then try fasting one day a week, plus three day in a row every month. When you can do this for three months, then you can attempt a seven to ten day fast one-four times a year. The real key, of course, is not the fasting alone but eating a healthy and cleansing diet between fasts. The best cleansing diet is one of raw fruits and vegetables with a few cooked nutrient dense, but low calorie greens added daily. This way you are cleansing and rebuilding your body to a higher state of health. Occasional fasts will help accelerate and intensify the natural cleansing, and help clear out the environmental toxins that are part of our modern lives.

I don't imagine this is the answer you were hoping for, but fasting is a serious undertaking. Done properly it can change your health and life for the better. When done foolishly or for the wrong reasons, fasting can be life-threatening.

A.J. Carlson, Professor of Physiology, University of Chicago, states that a healthy, well-nourished man can live from 50 to 75 days without food, provided he is not exposed to harsh elements or emotional stress. It was the Christian faith's icon, Jesus, who fasted for 40 days and 40 nights, that might be where that number came from. I hope this was of help to you.