Fasting as a means for improving health has been around since ancient Egyptian and Babylonian times. The modern day fascination with healthy fasting started in the 1800′s with the development with the of many alternative medical models i.e Naturopathy, Osteopathy etc. This was largely due to the short comings of allopathic (conventional) medicine at the time. Central to many of these models is the idea of Toxaemia, this being the slow accumulation of toxins and poisons in the blood and body tissue. Naturopaths and other alternative medical models claim this is the root cause of disease.
So why healthy fast? Well if Toxaemia is the cause of disease then you have to get rid of the toxins within the body, the fastest and cheapest way to do this is to fast. As your body goes into fasting mode it gradually starts to remove the acids and poisons from the cells of the body into the blood, these are then secreted through the skin and mucous membranes in the body, (the gut, nose, mouth,lungs etc). This means as you start to detox you can get things like a runny nose, bad breath, bad body odor etc as the body is starting to get rid of all the toxins.
Healthy Fasting also puts the digestive system into a state of rest which maybe beneficial for people with conditions such as Ulcerative colitis, Chrons disease etc. As mentioned before the gut will start to secrete toxins and poisons from about the third day, it is for this reason that many people on a fast decide to take enemas when fasting. As well as getting rid of the toxins beings excreted enemas also help to remove food which may have compacted into the colon. However evidence of the latter is limited, particularly as Colonoscopy has shown this doesn’t appear to be the case.
If considering a fast there are several types you can undertake, the first is called dry fasting. Dry fasting means you take no food or no drink of any kind including water. This is a very powerful fast and should only be attempted by experienced fasters or those under medical supervision (preferably both) and should last 48 hours at the most. The second type is called water fasting. This is perhaps the most popular type and involves eating nothing and drinking only purified water. The length of this type of fast depends entirely on the individual, however most seem to be 7-10 days long.
It is safe to continue for long periods of time however it is recommended you seek the advice of a alternative therapist experienced in healthy fasting, as breaking prolonged fast can be quite difficult. The last sort of fasting is juice fasting where you drink vegetable and fruit juices (freshly juiced at home) this extends the period of time you can fast, however it may not have such a strong detoxification effect as a water or dry fast.
If you wish to explore the idea of fasting further here are some books we recommend:

Just like to add that during a fast, don’t expect to carry on your normal duties as usual. Lie in bed and get plenty of rest. That means you’d have to be absent from work for the duration of the fast plus an extra few days more to regain your physical energy.
How you break a fast is also crucial. Re-introduce pesticide-free and easy-to-digest food very slowly as your system takes time to warm up.
Hope these tips help.