A new study of thousands of people reveals a wide range in the amount of water people consume around the globe and over their lifespans, definitively spilling the oft-repeated idea that eight, 8-ounce glasses meet the human body’s daily needs.The science has never supported the old eight glasses thing as an appropriate guideline, if only because it confused total water turnover with water from beverages and a lot of your water comes from the food you eat,” says Dale Schoeller, a University of Wisconsin-Madison emeritus professor of nutritional sciences who has been studying water and metabolism for decades. “But this work is the best we’ve done so far to measure how much water people actually consume on a daily basis — the turnover of water into and out of the body — and the major factors that drive water turnover.”