The eight glasses of water per-day standard is one of the easiest health rules to follow, since a person is almost always in the vicinity of a sink or a watercooler.

But according to Scottish doctor Margaret McCartney, it’s complete hogwash.  McCartney came out firing in a paper published in the British Medical Journal. In it, she argues that eight glasses a day is “thoroughly debunked nonsense” that has been hoisted upon the public by the bottled water lobby.

She also argues that the push for constant hydration is dangerous, because it can result in hyponatremia, a condition in which too much water lowers the percentage of sodium in the body to dangerous levels.

Naturally, push-back against McCartney’s paper has already begun, with medical professionals pointing out that the paper was not peer-reviewed, and accusing McCartney of cherry-picking data.

If this all has you confused, the Mayo Clinic simply recommends that “you drink enough fluid so that you rarely feel thirsty.”