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Comment by mark_l_watson | Hacker News Reader

3.2 liters of water a day is much less than 37 glasses of water. The article mentioned 3.2 liters.

In 1945 there was a recommendation that a healthy adult should have about 2.5 liters of water intake a day, including water that is part of the food you eat.

Somehow the media managed to drop the last part, and recommended you drink at least 2l water a day. Or even more.

Source: http://www.sciencealert.com/there-s-no-evidence-we-need-to-d...

I know of no credible research that shows that drinking more than required to still thirst is beneficial in a healthy human.

I am surprised by the down votes. I didn't realize drinking water was so controversial.

One data point: my neighbors, husband and wife, are a surgeon and a neurologist. We live in the mountains of central Arizona, and hiking is a favorite pastime. Both of these doctors say one should drink 1 quart of water an hour while hiking. I don't quite do that, but I certainly drink 2 liters on a strenuous 3 hour hike.

The claim you're supporting in the article is not about drinking water while on a strenuous hike in a hot, arid climate. It's about drinking water in routine, day to day life.

I was not 100% supporting the claim in the article. I was just pointing out what I thought was someone's error in converting 3 liters to 37 cups of water.

"37" was hyperbole.

3.2 liters of water (on top of all the water we already get from prepared foods, coffee, soda, etc) is still a _crazy_ amount of extra water.

Coffee is mostly water believe it or not. If someone tells you it doesn't count they are fail.

Anyone who has ever made coffee should have a fair idea of how much water is in it...

I think the concern people have with coffee is that caffeine is a diuretic, so you lose more water than you take in. While it's technically true that coffee does make you urinate more, it's a very tiny effect.

Except with regular use the diuretic effect goes away. There is no measurable difference in hydration levels of coffee vs non coffee drinkers. If it had a long term effect you would expect the coffee drinkers to be chronically dehydrated.

No, even in very short term use, the net effect of drinking coffee is to increase the amount of water in your body. The diuretic effect of the caffeine is more than offset by the water in the coffee (by a very wide margin).

That would be just over thirteen and a half cups of water, which may or may not be a lot depending on heat, humidity, activity level, and most of all, are you thirsty?

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