The accelerated healing process that occurs during fasting can scarcely be believed by a person who has not fasted. No matter how gifted the writer, the experiential reality of fasting cannot be communicated. The great novelist Upton Sinclair wrote a book about fasting and it failed to convince the multitudes. But once a person has fasted long enough to be certain of what their own body can do to fix itself, they acquire a degree of independence little known today. Many of those experienced with fasting no longer dread being without health insurance and feel far less need for a doctor or of having a regular checkup. They know with certainty that if something degenerates in their body, their own body can fix it by itself.
To whatever degree food intake is reduced the body”s digestive workload is proportionately reduced and it will naturally, and far more intelligently than any physician could order, redirect energy to wherever it decides that energy is most needed. A fasting body begins accessing nutritional reserves (vitamins and minerals) previously stored in the tissues and starts converting body fat into sugar for energy fuel. During a time of water fasting, sustaining the body”s entire energy and nutritional needs from reserves and fat does require a small effort, but far less effort than eating. I would guess a fasting body used about five percent of its normal daily energy budget on nutritional concerns rather than the 33 percent it needs to process new food. Thus, water fasting puts something like 28 percent more energy at the body”s disposal. This is true even though the water faster may feel weak, energyless.
After a day of water fasting the average person”s blood sugar level naturally drops; making a faster feel somewhat tired and “spacey,” so a typical faster usually begins to spend much more time resting, further reducing the amount of energy being expended on moving the body around, serendipitously redirecting even more of the body”s energy budget toward healing. By the end of five or six days on water, I estimate that from 40 to 50 percent of the body”s available energy is being used for healing, repair and detoxification.
Essentials of a Successful, Safe Fast
1. Fast in a bright airy room, with exceptionally good ventilation, because fasters not only need a lot of fresh air; their bodies give off powerfully offensive odors.
2. Sun bathe if possible in warm climates for 10 to 20 minutes in the morning before the sun gets too strong.
3. Scrub/massage the skin with a dry brush, stroking toward the heart, followed by a warm water shower two to four times a day to assist the skin in eliminating toxins. If you are too weak to do this, have an assisted bed bath.
4. Have two enemas daily for the first week of a fast and then once daily until the fast is terminated.
5. Insure a harmonious environment with supportive people or else fast alone if you are experienced. Avoid well-meaning interference or anxious criticism at all cost. The faster becomes hypersensitive to others” emotions.
6. Rest profoundly except for a short walk of about 200 yards morning and night.
7. Drink water! At least three quarts every day. Do not allow yourself to become dehydrated!
8. Control yourself! Break a long fast on diluted non-sweet fruit juice such as grapefruit juice, sipped a teaspoon at a time, no more than eight ounces at a time no oftener than every 2 or 3 hours. The second day you eat, add small quantities of fresh juicy fruit to the same amount of juice you took the day before no oftener than every 3 hours. By small quantities I mean half an apple or the equivalent. On the third day of eating, add small quantities of vegetable juice and juicy vegetables such as tomatoes and cucumbers.
9. Control yourself! The second week after eating resumed add complex vegetable salads plus more complex fruit salads. Do not mix fruit and vegetables at meals. The third week add raw nuts and seeds no more than 1/2 ounce three times daily. Add 1/4 avocado daily. Fourth week increase to 3 ounces of raw soaked nuts and seeds daily and 1/2 avocado daily. Cooked grains may also be added, along with steamed vegetables and vegetable soups.
Fasting can be divided into four phases.

1. Gastrointestinal Phase
The six-hour period following a meal, during which glucose, amino acids, and fat are absorbed into the blood, is the gastrointestinal phase. The hormone, insulin, is released from the pancreas into the blood in response to glucose and amino acids absorbed into the blood from the intestines. Insulin plays the major role in this phase and causes the liver and muscle to take the blood glucose into the cells and store it as glycogen. Insulin also allows all the other tissues of the body to take up glucose to be used as energy.
2. Glycogenolysis
The period following the gastrointesting phase, which continues for the next two days, is the glycogenolysis phase, during which time the liver and muscle, under the influence of decreased insulin and increased glucogen (a second hormone released by the pancreas), break down their glycogen to glucose. Glucose from the liver is used mainly by the brain, which can use only glucose for energy at this stage. (Red blood cells and the adrenal glands also can only use glucose, but they require much less than the central nervous system.) The liver glycogen supply of glucose lasts about twelve hours.
Muscle glycogen produces glucose for consumption by muscle. This supply may last twelve to twenty-four hours depending on activity. With decreased insulin levels, fat is broken down by the adipose tissue into fatty acids which are released into the blood and used as fuel by liver and muscle cells. After eight to ten hours one-half of muscle fuel is from fatty acids.
3. Gluconeogenesis
Although it begins a few hours after the last meal, in two days gluconeogenesis, the process of converting amino acids into glucose, becomes the major source of glucose for the brain. Non-essential proteins found in muscle and digestive enzymes are broken down into their individual amino acids which are then transported to the liver. The liver converts amino acids into glucose and urea. Urea is excreted by the kidneys, and the glucose is used mainly by the brain for energy. After two weeks of fasting, the kidney gradually takes on the majority of gluconeogenesis.
4. Ketosis
By the third day, ketosis becomes significant and increases up to the second week of fasting. Due to the low insulin levels and increase release of fatty acids from adipose tissue, the liver, under the influence of high levels of fatty acids, begins converting them to ketones to be used by muscle and brain for energy. As the concentration of ketones increases in the blood during the first two weeks of fasting, more is able to cross the blood brain barrier and supply fuel to the brain. In this way, the brain can use less glucose, and therefore, the demand for gluconeogenesis and breakdown of protein becomes less.
Protein consumption
The consumption of protein decreases from 75 grams per day in the first week to 20 grams per day by the end of the second week. Muscle tends to use mainly fatty acid and saves the ketones for use by the brain. It should be noted that protein is still a required source of energy.
“the replacement of muscle protein requires time and appropriate exercise”
Summary
In summary there are four biochemical phases of fasting during which the primary energy source changes from glucose to fat. In this way, energy supply is maintained to vital structures, such as the brain, and the use of protein for energy is minimized in the long fast. For individuals who will rest, there appears to be adequate energy stores, in the form of fat and muscle, to last many weeks.
Conclusion
It can be said, in conclusion, that fasting is a highly useful process when conducted properly and for the right reasons. Biochemical changes that occur during a fast return to normal afterwards. Fasting is neither a “cure” nor a “remedy.” It is one ingredient of a healthful and healing lifestyle and, if long term positive effects are to result, must be used in combination with the other requirements for health; natural diet, exercise, emotional poise, and clean environment.