Something further to add here, is that water-only-fasting is not considered by many (including yours truly) to be the ideal method of losing weight. The reasoning behind this is that during the fast and from its outset, the metabolic rate is lowered by two fifths to one quarter in the bodys efforts to conserve food reserves in the ultimate prevention of actual starvation, and therefore you burn far fewer calories: this is a biological and physiological legacy from within the eons of time.
The best way to lose weight and by far the quickest and most expedient, is to follow the regimen of "Eat To Live" outlined here............. http://www.drfuhrman.com/weightloss/default.aspx