
You Do Not Have to Drink 8 Glasses of Water a Day - denzil_correa
http://www.nytimes.com/2015/08/25/upshot/no-you-do-not-have-to-drink-8-glasses-of-water-a-day.html?_r=0&abt=0002&abg=1
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mangeletti
Without any disrespect to the author, why don't we all just start thinking for
ourselves when it comes to our health, rather than being told contradictory
information every 3 years by mainstream media?

One minute it's best to eat ice cream for breakfast; the next minute we
shouldn't eat any carbs at all; then we should start drinking red wine every
day; then more water; then less water, etc. It's as if we're just a big
experiment or some sort of inside joke to the mainstream media.

~~~
dekhn
Are we all experts who are capable of thinking for ourselves ("thinking for
ourselves" seems to equal: inspecting the primary literature, or review
literature, and coming to a conclusion)? No, we're not.

Thinking for yourself is untenable- we need scientists who are experts in
analyzing data to provide specific suggestions, and disseminate those in the
media. Unfortunately, there is little consequence to reporting false
conclusions, or inaccurate health data, so I don't see any change forthcoming.

~~~
mdpopescu
Out of curiosity, do you realize that the same thing can be said about
religion? You don't know enough about it - definitely not as much as the
people who specialize in it - so you should listen to your priest on the
subject. Or politics: just pick a party and follow its lead, politics is a
complex subject and you can't know as much as the professionals.

~~~
dubya
Protestants, at least, have the idea of the "priesthood of all believers",
meaning roughly that each person can have authority in doctrinal matters. So
you should listen to your priest, but you don't have to accept that he's
correct if God is telling you something different. Thus the billion different
protestant denominations.

~~~
zaphar
Protestants if you go back to their roots actually _expected_ you to become an
expert in scripture in order to recognize when your "priest" is wrong. But
they didn't promote anything goes. It's more that you should learn and be able
to apply scripture correctly. This didn't prevent the proliferation of
denominations because of course different people would interpret a piece of
scripture differently and get really worked up about it.

~~~
yellowapple
This is in contrast with Catholicism, where pretty much everything was
conducted in Latin rather than local languages; the emphasis on layperson
understanding of theology was a direct response to the trend of most followers
having zero understanding or ability to understand the scriptures and sermons
they were expected to follow.

Of course, this also resulted in the more decentralized power structure
relative to Catholicism's. Quite a bit of Protestant philosophy and tendency
stems from immediate responses to a perceived-to-be corrupt and exclusive
Catholic Church.

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mikhailt
> The human body is finely tuned to signal you to drink long before you are
> actually dehydrated.

Easily said than done. This is only true if the body is healthy in the first
place, once you starts messing it up with unhealthy diet (especially high-in-
sugar and salt diet) and so on, your body will confuse thirst with hunger. You
have no idea how often people confuse both, the body will be happy to eat any
food because most food has water in it.

The reality is that water is about the easiest and healthiest thing people can
do and yet, in US, it's more common to see people drinking juices, soda, and
any other sugar beverages with zero pure water drinks.

For people who can't think for their health, telling them to drink 8 cups of
water and nothing else is the best thing we can do. Once they do, they are
likely lose a lot of weight without any exercise. Unfortunately, it is more
likely they won't follow through because sugar is an addiction that is not
easily given up by the body.

~~~
yellowapple
Not to mention that such a signal doesn't always come early enough to consume
water before dehydration sets in, particularly during long-term physical
activity (i.e. running long distances every day); if you slack off on water
intake because "well I'm not thirsty right now", by the time you start feeling
thirsty again, it's pretty likely that you're already dehydrated.

Really, the whole "8 bottles of water a day" thing depends on physical
activity levels. A sedentary person might just need one or two glasses of
water, tops. A person who's running for hours a day might easily go through
several gallons.

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branchless
If I go for a pee and it's yellowish I have more water. Also I do it when I'm
thirsty.

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jtolj
They mention this in the article, but bears repeating - if you don't want to
get a kidney stone (and believe me, you don't) 8 glasses a day is probably not
a bad idea.

~~~
jedberg
> if you don't want to get a kidney stone (and believe me, you don't)

To put some perspective on that, I recently had one and it was the worst pain
in my life. I asked some women who have had both a stone and a natural
childbirth which was worse, and they said the pain is about the same.

The difference is that at least you know +/\- about a month when you're going
to have a child and can prepare; with the stone, you're just suddenly in
excruciating pain.

~~~
bkmartin
And, at the end of childbirth you get the joy of having a baby... no one has
cake every year to celebrate the birth of their kidney stones.

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jbb555
Yeah, there are number of people I know who are otherwise intelligent who seem
to blame almost every minor ailment they have on being "dehydrated". And when
I say I'm not dehydrated because I have 2 small glasses of water, 2 cups of
tea and coffee almost gasp because "coffee dehydrates you".... No. Actually it
doesn't. It's about 99% water...

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forkandwait
The forkandwait/ ancient Greek ideal diet: A bunch of whole grain bread, fish,
olive oil, and all the random seasonal fruits and vegetables you can get your
hands on, but don't eat until you are full. Every once in a while gorge on
meat and dairy and honey. Get lots of exercise. Don't get killed in battle,
get enslaved, or die in an epidemic.

There should be a special name and place in hell for all the diet bullshit
that goes through the culture like this.

Not that i follow my own advice or anything...

~~~
sp332
And yet, there is no country in the world that has lower life expectancy now
than 200 years ago. [http://www.maxroser.com/everyone-is-better-off-life-
expectan...](http://www.maxroser.com/everyone-is-better-off-life-expectancy-
increased/)

~~~
dkersten
My completely uninformed made up argument: medicine, medical care and
sanitation have improved a lot. ;-)

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suprgeek
There are two main problems with science & especially health research "news".
First is the urgent need of the Media to "sell more papers" (Or whatever the
digital equivalent). Nothing sells more than vaguely alarmist news that is of
concern to everybody. So "Drink 8 Glasses of Water every day or suffer the
consequences" is an excellent hook to draw-in almost everybody.

Second the ability of companies to influence the research - If the research
shows a slight problem with Milk (for example) you can bet that the dairy
industry will promote another conflicting study that shows Milk is just GREAT!

Now the consumer is completely alarmed and confused by these two trends - so
it always was and always will be.

~~~
jonlucc
Even if you only have disinterested, non-partisan scientists performing very
rigorous studies, the science on this stuff is _hard_ and layperson takeaways
are nearly non-existent.

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moron4hire
I generally think, if you feel off and can't figure out why, the first thing
you should check is your water intake. A lot of people live with mild
dehydration and don't know it. I know I did for a very long time. It's amazing
the difference in how I feel when I'm drinking "enough" water and when I
don't. There is always the possibility it could be something else, but check
the water first.

I basically just fill up a 64oz beer growler with water in the morning and
make sure I get through it by some point in the day. That's enough to get me
feeling great and not like I just want to stay in bed all the time.

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tormeh
The EFSA recommends[0] 2.0 litres of water for women and 2.5 litres of water
for men, so there's that. The governmental organizations' advice is slow-
changing and well-founded. Unless you want to flip-flop along with the
freshest preliminary research I would say it's your best bet.

0:
[http://www.efsa.europa.eu/en/press/news/nda100326](http://www.efsa.europa.eu/en/press/news/nda100326)

~~~
IkmoIkmo
Did you read his article and looked at what you're referencing?

From the website you're referencing:

> Adequate Intakes (AI) have been defined derived from a combination of
> observed intakes in population groups with desirable osmolarity values of
> urine and desirable water volumes per energy unit consumed.

The article attacks exactly that line of reasoning:

> I’m a pediatrician, and I can tell you that I have rarely, if ever, used
> urine osmolality as the means by which I decide if a child is dehydrated.
> When I asked colleagues, none thought 800 mOsm/kg was the value at which
> they’d be concerned.

More importantly, intake of water != drinking water.

95% of lettuce is water, on the extreme end, but it's not unique. 90% holds
for carrots or beets, too. For potatoes it's about 70 to 80%. And when cooked,
it soaks up even more water. That adds up quickly and severely reduces the
amount of glasses of water you actually need to drink. After all, 2.5 litres
of water would easily amount to (over) 8 cups/glasses of water. The article
attacks exactly that notion.

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acomjean
When I was treating water to drink while traveling I would 2 liters a day.
That seemed to be right on the edge of being thirsty a lot while being fairly
active

I drink more than that now. But it gives me an excuse at the office to get up
and walk to bathroom then walk around. So its not just the staying hydrated.
Plus its hard to drink too much water and better for you generally then other
liquids.

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bitsoda
If you're thirsty, drink water until you're no longer thirsty. If you're not
thirsty, don't drink water.

~~~
onion2k
How do you know you're thirsty? For a start, there are _a lot_ of medical and
neurological issues that can stop you feeling thirsty (diabetes etc). A large
percentage of the population don't have the correct hormone response that
tells them to drink. Secondly, especially in Western societies, there are
social conventions that mean we always have a drink with food. That creates a
conditioned response that means many people _literally_ mistake thirst for
hunger, so when they feel thirsty they eat something. (That also contributes
to obesity.)

'Drink X glasses of water a day' is a simple adage that mitigates all these
problems with very little risk.

~~~
bkmartin
"A large percentage of the population don't have the correct hormone response
that tells them to drink." Please define large percentage and offer a
reference to this fact. The point made in the article was based around
"otherwise healthy idividuals"... not people who have a health issue that
would not let them know they are thirsty.

~~~
onion2k
That was hyperbole on my part really. There are about 10% of people with some
form of diabetes, and one or two percent for the other conditions. That's a
'large percentage' if you compare it with other unifying factors across the
population (you can't say '12% percent of people have X condition' for many
medical problems), but I guess it's not strictly a large percentage on it's
own.

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dingaling
Why is this still a 'thing' capable of causing contradictory advice?

Over the past three decades most Western armies have developed water-
replenishment rates based on environmental conditions and activity. They based
these on actual empirical studies of performance and illness ( and fatality )
rates. Not dietary fads.

Here's the US Army tables. The British Army ones are similar and are even more
stringently applied, due to several incidents of soldiers dying because they
tried to preserve their water. The squad now stops and drinks its water en
masse.

[http://www.evans.amedd.army.mil/PM/WorkRestTable.pdf](http://www.evans.amedd.army.mil/PM/WorkRestTable.pdf)

I only wore blue but even then if I showed-up on exercise with the wrong
quantity of water loaded for the conditions it was a charge.

~~~
ilaksh
That says if you are doing 'easy work' you should drink 1/2 qt. per hour +/\-
1/4 qt/h +/-1/4 qt per hour = 0-1 qts per hour depending on the person and
conditions.

In other words it doesn't really say a lot especially for people who aren't
soldiers marching in the sun.

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jqm
It all depends..

I was a landscaper in Phoenix AZ for a few years. Over the summer. We usually
got to work ~5:00 AM and went home about 1:30-2 but it was still extremely hot
(regularly 113F or 45C) . I regularly drank over a gallon and half of liquid a
day. And was still somewhat dehydrated. Drinking that much fluid a regular
basis really starts washing salts out of your body... along with the sweat.
You become very sensitive to amount of dissolved solids in liquid. Water
starts being extremely unsatisfying at the days end but drinking salty stuff
(Gatorade etc) at the wrong time (early morning before you really have drunk
much) will really lay you out as it heats up.

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neverminder
No, You Do Not Have to Trust What Mainstream Media Says Every Day.

~~~
lcswi
'Mainstream media'? I mostly hear nutrition tips like this via Facebook posts
of dubious pseudoscience lifestyle sites.

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Camillo
Yes, your body will let you know when you are thirsty. But I think it's still
important to remind people to _drink_ when they are thirsty (you'd be
surprised at how often people try to hydrate by _eating_ instead), and to
drink _water_ when they are thirsty (not soda or fruit juice or coffee).

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Oletros
No, you don't have to drink 8 glasses of water, nor 2 nor 12, you have to
drink what your body needs and asks for

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sp332
Only 8 cups? My throat is uncomfortable if I drink less than that at work, and
I drink a lot at home too.

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lazyant
Somehow related, very rare but good to know
[https://en.wikipedia.org/wiki/Water_intoxication](https://en.wikipedia.org/wiki/Water_intoxication)

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weka
I would think that not every human, regarding their weight/age/height, would
not have to drink the same amount of water.

Water is delicious, though.

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traviswingo
Aldo respect, this article is a waste of time. We're so obsessed with putting
a number on everything - that's why the "8 glasses a day" rule exists. It's
not literal. It means "drink a lot of water throughout the day and you'll feel
better." Which is true. I drink tons of water and it's made a massive
difference in every aspect of my life. I have no idea how much I drink daily,
though. It doesn't matter. Because we're all different. Just drink more water,
and stop trying to figure out that magic number by reading articles from the
media that change every week.

~~~
IkmoIkmo
If you read the article he's basically saying drinking 'tons' of water is
completely unnecessary and not linked to any evidence of benefits to your
health, contrary to what you're saying. He's a scientist, you're speaking from
personal experience, which is as valid as people saying they feel much better
after praying to their pet lizard every night (i.e. it may be valid, it may
simply be a placebo, and it may simply be unrelated entirely).

