Drink More Water, Says FLOTUS—But How Much?

A call for drinking more water is reason to consider the "eight glasses a day" dictum. Pssst: It's not true!

Which raises the question: How many glasses of water a day should you drink?

It's commonly believed that eight 8-ounce glasses of water should be guzzled each day. You sure won't get any arguments about that from the bottled water industry. But hydration experts aren't sure where the "8 x 8" rule came from—or whether it holds water.

Mike Sawka, a U.S. Army research scientist, thinks the origins lie in a 1933 study on rodent hydration. The research led to a recommendation of 2.5 liters a day, or 84.5 ounces of liquid, for a moderately active human to make up for water lost to sweat and excretions. He says that 20 percent of those ounces come from foods that contain a lot

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