Detox!!
The main reason why fasting provides a health benefit is because the action of fasting puts the body into a state of detoxification. Fasting offers a time period of physiological rest, for your digestive system in particular, and it makes your body revert its focus to self-healing, strengthening or repairing internal organs. During a fast, your body will cleanse itself of various waste products and toxins which have accumulated in your cells.
Watch it happen... the Urine Signal:
During a water fast, it is interesting to notice that within the first day or so, your urine will go from clear at first, to more yellow later, which will seem backwards - if you are only giving your body water, you might expect it to go totally clear. This is one of the indicators that tells you the fast is helping to cleanse your body of unnecessary toxins.
Push the "reset button" and reduce sugar cravings:
Another benefit which makes fasting popular among those trying to lose weight is that it resets your system, and can reduce your subsequent craving for sugar. During a fast, you are giving your pancreas a nice rest from having to produce insulin, which it normally does while food is being processed in your digestive system.
After this period of low insulin production, you will notice a much lower desire to eat sugar, which will be very helpful in curbing a sweet tooth in helping you shift towards a more healthy selection of foods, helping you to lose weight and burn fat.