8 glasses of water per day? Rubbish!

I’m glad to see that finally, some sci­entific invest­ig­a­tion is being done on this old canard. And it turns out you don’t need to drink litres of water per day at all:

Accord­ing to Heinz Valtin, a retired pro­fessor of physiology from Dart­mouth Med­ical School who spe­cial­ized in kid­ney research and spent 45 years study­ing the bio­lo­gical sys­tem that keeps the water in our bod­ies in bal­ance, the answer is no.

The National Academy of Sciences’s Insti­tute of Medi­cine also researched this in 2004:

Its panel on “diet­ary pref­er­ence intakes for elec­tro­lytes and water” noted that women who appear adequately hydrated con­sume about 91 ounces (2.7 liters) of water a day and men about 125 ounces (3.7 liters). These seem­ingly large quant­it­ies come from a vari­ety of sources—including cof­fee, tea, milk, soda, juice, fruits, veget­ables and other foods. Instead of recom­mend­ing how much extra water a per­son should drink to main­tain health, the panel simply con­cluded that “the vast major­ity of healthy people adequately meet their daily hydra­tion needs by let­ting thirst be their guide.”

So there you go. Your body has a per­fectly good way of telling you it needs a bit of top­ping up. Short of an ill­ness that requires you to over-hydrate, or weather requir­ing the same, drink when you’re thirsty and stop worrying.

Via Sci­entific American