When you diet and put your body through extreme physical stress you need those essential minerals that are in water.
Also, some people are on a distilled water kick, b/c they fear the pollution of their water. However, why add Crystal Lite if you fear chemicals? It doesn't make any sense. Also, normal food caontains about a 10:1 contamination ratio as compared to water. So, unless you guys are eating totally clean, i.e. buying only certain foods from Whole Foods, Central Market, etc., WTF is the point?