You shouldn't drink only water...you need the vitamins from the foods you should be eating. But, on the water thing...drink at least 8 regular size glasses a day. To keep from eating too much, drink one or two glasses before each meal. I hope this helps. This reduced my food intake, until I got lazy and stopped drinking the water before my meals. I believe that i could have lost the weight if i would have kept it up and exercised. So, try it, don't give up, and hopefully it will help. i have a hundred pounds to lose before i am of healthy weight...i think i'll try the water thing again. Good luck.