do not drink only water...its bad for u...u shouldnt drink it before ur meals either because it blocks ur digestive system. u cant starve urself and drink water instead to replace a meal because ur not gunna get full and ur body needs vitamins from the food u eat. first of all ur not gunna get full because when u eat(chewing food) ur brain tells ur body that u are putting nutrition and vitamins and all the healthy things in it but when u drink it doesnt do anything because it thinks that u are just putting fluids in.