While I agree that drinking water is important I disagree with the argument of one does not find coffee and juice in nature so it shouldn't count. I don;t see how this is the least bit relevant to people's hydration levels. The easiest way for the general population to monitor water intake is urine color. If your urine is consistently clear you're good. Anyways good article besides the nature thing.
RE: How much water should you drink per day?