Distilled water uses heat to basically boil out all the minerals -- that's why it's used in car batteries, for example, because it doesn't have the minerals drinking water
has to clog up
the works. But the body needs minerals, and you don't want to leach them out, which is what'll happen if you drink distilled water regularly. Now, some people do it, particular those with particular conditions that require them to leach minerals out of their systems.