How much water do you REALLY need?

As many people know, the "rule" that you should drink eight glasses of water a day is a complete shot in the dark, fabricated whole cloth by a military technical writer in WWII who just needed to come up with an amount to recommend. He picked eight 8oz glasses because it sounded about right, and we have been slavishly following this dictum ever since.

Researchers have finally tackled this question, and their results are surprising. Women should be drinking nine cups of water per day, and men should be drinking thirteen cups per day. But food and other beverage intakes count, too - not just tea and soda, but foods like apples (6 ounces of fluid) count against your total.

Long story short? It can't hurt to drink more water (to a point).

Image courtesy Flickr/allaboutgeorge