This article is from the Alternative Medicine Therapies guide.
Published research into therapeutic fasting first appeared in the late nineteenth century. Since that time articles have appeared in conventional medical journals in both the United States and Europe showing the positive results of supervised fasting in treating various diseases, including obesity, cardiovascular disease, autoimmune disorders, diabetes, skin disease, gastrointestinal disease, arthritis, and allergies. How fasting positively affects these diseases, and what its long-term effects are, depends on the ailment. If you have a chronic medical problem and are interested in the benefits of fasting as a therapeutic modality specific to your condition, your best bet is to locate a nutritionally oriented physician or naturopath with some experience in the field.
There is very little published evidence that fasting has any value for a healthy individual. Even so, practitioners of naturopathic medicine regularly recommend fasting as the therapeutic tool for internal cleansing, otherwise known as detoxification. Periodic fasting, naturopaths believe, helps overworked systems (the gastrointestinal tract, skin, liver, and kidneys) remove potentially damaging toxins from the body.
Not surprisingly, a naturopath's definition of what constitutes a "toxin" vastly exceeds that of conventional medicine. And while both camps tend to agree that certain heavy metals (lead, cadmium, mercury) and chemical compounds (pesticides, herbicides, solvents) are toxic, naturopaths expand the list to include food additives, many commonly prescribed drugs, cigarettes, recreational drugs and alcohol, and substances produced by bacteria-induced chemical reactions in the intestine.
In addition to using fasting for cleansing purposes, many healthy individuals find it a useful way of weaning themselves off of unhealthy foods. A fast of no more than three days can be used to launch a healthier diet--for example, changing to a vegetarian diet from a meat-based regimen.
A fast can also be an effective way to begin a low-calorie diet, a signal to your body that you're altering the way you eat. But the hunger produced from a fast can lead some people to binge afterward. The "yo-yo" effect of fasting and binging can slow down metabolism, making it harder to lose weight in the long run.