Drinking eight glasses of water – An Urban Legend?

Yes. That is what this article says. Quoting a 2002 report in the American Journal of Physiology this article says that, drinking eight glasses of water a day in order to stay healthy may not be necessary.

It also adds that “If you drink enough fluid so that you rarely feel thirsty and produce one to two liters of colorless or slightly yellow urine a day, your fluid intake is probably OK.”

So, how much is truly enough?