By consuming only water and fresh fruit, you are technically on a juice fasting diet plan. You are also allowed vegetable juices (salt, sugar and additive-free) for a set period of time - usually from one to five days.
With no protein, fat or complex carbohydrates, this is the ultimate in low calorie diets but it is inclined to slow the metabolism with the result that fewer calories are used.
There can be little doubt that juice fasting diet plans are simple to follow, as there is almost no choice about what you can eat or drink. Often seen as another way of ridding the body of harmful toxic substances, it is claimed that it can increase the ability to concentrate and think rationality. However, most people on juice fasting plans experience some degree of physical weakness and mental confusion.
Supporters argue that such side effects (others include persistent headache, dizziness, nausea and fatigue) are all part of the physical process of getting rid of waste products and that they should be seen as a sign that it is working efficiently. It is thought that the body can divert the energy it would have used in digesting cooked food and direct it instead to repairing and renewing damaged cells. The actual process of making suitable drinks breaks down the fibres in the fruit and vegetables and releases the vitamins and minerals that were locked within them. This is work that the body would normally have had to do which is why there is surplus digestive energy. In addition, more nutrients are made available. The fact that a bout of ill health usually results in a decreased appetite is sometimes cited as evidence that when the body is under stress it needs to channel energy away from the usual digestive processes and concentrate instead on maintaining organs and tissues.
Only fit young adults with no health complaints should consider such a restrictive diet for anything longer than24 hours and even then medical guidance is advisable.