Fasting is often prescribed for medicinal purposes and used by certain religious beliefs as and integral part of their customs
The act of fasting for weight loss, however, simply is not recommended and this is the reason why. Fastingtricks the body into thinking you are 'marooned on a desert island without food and water' scenario and this starts the body's 'Famine Response' (skipping breakfast and meals has the same affect!!) This leads to a slower metabolism for survival and eventually weight gain when you return to a normal eating pattern. If we do not fuel our body it then must find its energy from different sources. The first comes from the liver and its glycogen stores and then from fat by using up the fatty acids stores. If you still have not eaten it then moves to other areas protein storage, i.e.: our muscles and other soft tissue. Our nervous system depends on glucose to function properly; this includes your heart and your brain.
Drinking hot water will 'increase' your metabolism.
While drinking a cup of water mixed with lemon juice, grapefruit juice and a teaspoon of honey first thing in the morning will wake up the gall bladder and prepare the liver for the oncoming breakfast and does detoxify your system - there is absolutely no scientifically based evidence that it will boost your metabolism. If anything it is said to be good for the bowels and we all know that warm to room temperature water is more readily absorbed by the body, however, having said that the best form of drinking water is - cold. Various fitness professionals note that water can help as a fat burning tool simply because it helps in the flow of energy, assisting in the transportation of vital nutrients to our cells where it is burn as fuel.