The act of fasting is a deeply spiritual one. It is repeatedly mentioned in the Bible and other religious texts as being a method to come closer to God and to "prove" one's spirituality, or even to demonstrate one's willingness to cast off the cloak of flesh that we wear.
Christians honor the forty days and forty nights of Christ's fast and seclusion in the wilderness with Lent. It is a time when people give up some trivial thing such as candy or watching TV for forty days.
Fasting has been heralded as useful for anything from spiritual enlightenment to a miracle cure for the body. I have read that it can (supposedly) cure cancer and illness, aid meditation, and so on. What is more certain is that it can aid weight loss, detoxify the body, and relieve symptoms of food allergy and intolerance. It is among our natural defenses against illness (we lose our appetite when ill) and one of our natural responses to grief.
I find fasting to be especially important at this moment, because we are in the midst of an epidemic. The amount of food served in typical restaurant portions is enough fuel to sustain one for a day or two. And that's just one meal. The average American eats nearly 4000 calories per day. The average human being requires less than half of that per day, preferably in primarily natural/raw states.
We consume large quantities of refined carbs and processed foods, things which have been preserved and sterilized and injected. Nature's foods, perfect sustenance as they should be, are deep fried, salted, genetically altered, selectively bred, condensed into syrups or ground to powders, remixed, recombined, and extruded to achieve foods which are super-flavored to the point that natural foods seem to have no flavor (when they actually have it in abundance).
There are thousands of diets, with tons of new ones every year, that tout some way or another of eating "just this" or "just that" to miraculously lose weight and feel better. These diets each work for some people some of the time because they have a small piece of the right idea but then fluff it over in the guise of allowing gluttony or some other comfort. A good example is that with the Atkins diet, you cannot consume processed flours and sugars in any quantity, so it reduces these potentially toxic foods from the body. On the low fat diet, you are restricted from eating overly processed meats and cheeses and fried foods, which again reduces potentially toxic foods from the body. However both of these diets allow for the continuation of some toxic foods, which is why they can never completely succeed.
Returning to the way that humans had to eat prior to our agricultural days is an excellent method to returning to health. This natural way of eating included completely unprocessed foods, foods eaten only when they were fresh and usually ripe, natural fasting, and consumption of little sugar and lots of water. When animals were eaten, all of the animal was eaten. Organs, fat, light and dark meat, skin, even marrow and brain. Humans ate foods based on the season, because they didn't have the luxury of flying fruits in from warmer climates during the winter.
I propose that a return to such a way of eating, and including deliberate fasting is a method to improving whole body health - not just to lose weight. Beginning with a fast is probably the easiest way to start the diet - this time spent not eating will allow the body to break it's addictions to sugar, carbs, nicotine and caffeine. This way, when you begin to eat as nature intended, you have already broken the bonds to your previous way of eating. The added benefit is that the fast has changed the way you taste food. Anything you eat after a lengthy fast will taste amazing - even something so simple as a piece of cucumber. After a fast you will rediscover the way food is supposed to taste and just how much you enjoy simple, raw, natural foods. Most of us today grew up eating foods that were over seasoned, over mixed, and over processed. Even home cooking saw a lot of this, as our moms used canned tomato sauces, pre-made pastas, mayonnaise, salad dressings, processed cheeses, canned fruits and vegetables. You cannot understand how over saturated with flavor most store bought foods are until you spend time eating a diet which does not have this saturation. After some time spent on a natural diet you may even find prepared foods completely distasteful and they could cause stomach upset because they are things your body should reject but has developed a tolerance.
An ideal, very healing and cleansing fast is described as 30-40 days. This is the duration of Lent. The length of the fast is important, as we are more affected by lunar/solar cycles than we realize, and a fast lasting more than 30 days covers an entire lunar cycle and all the changes in our mood and bodies that comes with that cycle. Whether you hold any belief regarding the spiritual significance of the moon, you cannot deny that there are slight changes in the gravitational impact on earth during it's cycle as evidenced by the tides. This has biochemical effects on all life on earth, which is what lead to the perception that people act differently around the time of a full moon. The additional significance of Lent is that it is a recurring yearly event. To fast every year on Lent (water, juice or fruit fast) would be a habit that will keep you in a cycle of healthier eating. It will also help to break the bonds of "need" in your mind that keep you tied to the American idea of what is appropriate amounts of food to eat.
When you fast you will find (as most people do) that you actually have more energy and feel better as the fast goes on. It provides reset time for the body, it cleanses and allows your digestive tract to heal itself without distraction. The energy normally used for digestion (which is quite a lot), is put towards more important things like repairing your body. It has also been said (and this may be more theoretical) that when your body begins to consume some of it's own tissues, it takes the old, diseased, and dead tissues first.
A statement like that, if true, could uphold the idea that fasting can cure cancer. Cancer is damaged tissue that is replicating itself, when that replication should have been turned off because the tissue is damaged. If the body goes after damaged tissue first, then fasting should consume that cancerous tissue along with any other tissues in the body that are past their peak. Then when one returns to eating, the body will regenerate new tissue to replace those which were consumed. It seems it is universally accepted that when the body is starved and turns to consumption of it's own tissue, it's a terrible thing. Maybe we, in our overfed and fat society, are making assumptions based on less fact than they should be.
Medical science is beginning to accept the fact that fasting is actually good for the body, and perhaps someday we will learn that fasting is also necessary for the body to maintain it's own good health. After all, the Bible tells us so in it's own way, as it always does.