Daily water consumption

[obbn]

Hello Again All,
I have always heard that an adult is supposed to drink something like 8 glasses of water a day. I have to say that I am guilty of not drinking 8 a day, but my wife is. Of course that leads to her "preaching' the water thing to me.

My thought is the although I don't drink 8 glasses of water a day I do drink plenty of liquid. I must confess that I am a Ginger Ale addict, probably drinking 4 or 5 a day. Plus things like Fuse and Orange Juice. Reading the ingredients in all of these drinks shows me that the main ingredient is water. So, does the water content in these drinks count towards your daily water consumption? Yes, there are other ingredients in the drinks but would that take away from the water content?

[Ferret Herder]

There's no evidence for that. (http://www.scientificamerican.com/article.cfm?id=eight-glasses-water-per-day) Otherwise-healthy people can let thirst be their guide.

[Ambivalid]

Yes, it all counts. Don't worry about meeting some arbitrary quota. Just drink when you are thirsty.

[Turek]

Define "glass" as a unit of volume.

[obbn]

There's no evidence for that. (http://www.scientificamerican.com/article.cfm?id=eight-glasses-water-per-day) Otherwise-healthy people can let thirst be their guide.

Thanks for the link. Confirms what I suspected. For some reason when "advising" me on my water intake, my wife discounts my beverages of choice saying that they don't count and only pure water does. I always thought it was bunk and the article confirms it.

Although I won't tell my wife, better to let her think she is right!

[dolphinboy]

My wife and I have the same argument. She drinks lots of water each day, I only drink when I am thirsty. She claims that you MUST have the equivalent of 8 glasses a day. Even Dr. Oz disagrees. Of course she pees a lot more than I do...

[njtt]

My wife and I have the same argument. She drinks lots of water each day, I only drink when I am thirsty. She claims that you MUST have the equivalent of 8 glasses a day. Even Dr. Oz disagrees. Of course she pees a lot more than I do...

Well, if she's not going to believe you about water, she's not going to believe anybody!

[Joey P]

Define "glass" as a unit of volume.

I believe it's technically supposed to be 8 "cups" of water a day but since most people interchange cup and glass not realizing that the medical community might be using cup to mean 8 ounces they say glass and things like this (what you said) happen.

Also, from what I've heard, 8 cups a day turned out to be pretty arbitrary. IIRC, doctors seem to agree that most people don't drink nearly as much water as they should, but 8 cups isn't some magic amount.

ETA Here's (http://www.mayoclinic.com/health/water/NU00283) what the Mayo Clinic has to say about water consumption. They also mention '8 oz glasses' in on the linked page.

[scootergirl]

I am really bad at drinking what is considered the optimum daily amount of water. I believe I get enough in other ways. There are times however, like now....I have a bladder infection, in which I increase my intake just to flush things out.

[Ferret Herder]

ETA Here's (http://www.mayoclinic.com/health/water/NU00283) what the Mayo Clinic has to say about water consumption. They also mention '8 oz glasses' in on the linked page.
Their second page (http://www.mayoclinic.com/health/water/NU00283/NSECTIONGROUP=2) does go on to say that if you rarely feel thirsty and produce about 6 c/1.5 l of light-colored urine a day, you're doing well with whatever you're consuming.

[Musicat]

Thanks for the link. Confirms what I suspected. For some reason when "advising" me on my water intake, my wife discounts my beverages of choice saying that they don't count and only pure water does. I always thought it was bunk and the article confirms it. It's bunk in so many ways. Most fruit juices, coffee, etc., are mostly water. Consider drinking a glass of water, then put a few drops of fruit juice in another. Does the fruit juice cancel the water? Nonsense. Your body doesn't have a problem with water mixed with other things.

Besides, once it is in the stomach, it is mixed with other stuff, anyway, before being digested. You stomach doesn't keep a separate compartment for "water only."

[Hari Seldon]

It is mostly nonsense. Yes, you need roughly 64 oz of water a day, but it comes from many sources: plain water, soda, coffee, tea, from metabolizing carbohydrates and from foods that are often mainly water. I think typical vegetables tend to be 80-90% water and it all counts. How could evolution fail to produce creatures that are thirsty when they need more water? Even my family doctor subscribes to this myth. What does Snopes say?

[Jenaroph]

Snopes (http://www.snopes.com/medical/myths/8glasses.asp) repeats the information in many of the links here (that 8 glasses of water is not a necessity) but also brings up a possible source, a physician who - surprise surprise! - wrote a book about the magical cures that drinking way more water than you need will bring, without any doing scientific studies that would back up his claims.

[zwede]

A while back I saw something on TV about women who always have a couple of water bottles in their purse and go sipping them all day ending up in the ER with kidney failure. According to the TV story "water ODs" had become a common occurrence. Any truth to that or was it just media exaggeration?

[isaiahrobinson]

A while back I saw something on TV about women who always have a couple of water bottles in their purse and go sipping them all day ending up in the ER with kidney failure. According to the TV story "water ODs" had become a common occurrence. Any truth to that or was it just media exaggeration?

Very much an exaggeration. It is possible to get water intoxication (http://en.wikipedia.org/wiki/Water_overdose), which is when you drink so much water that it starts shifting into cells in excessive quantities via osmosis, causing the cells to start swelling. Eventually if the cells swell too much it can cause damage to the brain and central nervous system. However the condition is very rare and you really have to drink a huge amount of water to cause it - there's no way it could happen by sipping a few bottles of water all day. Most cases have involved people in water-drinking contests, or people who have been drinking two or three liters of water an hour as part of diet programs.

As far as the original question goes, 6 to 8 glasses of water a day (just over a liter a day) is a decent recommended amount (http://www.nhs.uk/Conditions/Kidney-stones/Pages/Prevention.aspx), but it's by no means a requirement and it varies considerably between different people. A better means of judging it is by your urine - it should be clear or a very pale yellow. If it's golden yellow or dark yellow, you're not drinking enough water.

[tripthicket]

A better means of judging it is by your urine - it should be clear or a very pale yellow. If it's golden yellow or dark yellow, you're not drinking enough water.
Not to dispute the above, but I throw in another variable: some years ago, I used to take a chewable flavored vitamin supplement. It turned my urine a very bright yellow (what I personally call "Screaming Yellow" -- not because it's painful, but because it was so bright I comically opined that it made my eyes scream just looking at it). In effect, I guess I was taking a daily Food Coloring supplement. :eek:

[taffygirl]

Their second page (http://www.mayoclinic.com/health/water/NU00283/NSECTIONGROUP=2) does go on to say that if you rarely feel thirsty and produce about 6 c/1.5 l of light-colored urine a day, you're doing well with whatever you're consuming.

According to my GYN, "light" means very pale straw color or lighter. This, he says, is easier for men to gauge; with women, the urine immediately diffuses in the toilet water, so many women think they're getting enough fluid when they're not.

I'm one of those people who can't go by thirst. I just don't get very thirsty, so tend to have trouble from mild dehydration. Plus I'm a teacher; the same doc says teachers tend to drink too little water because we can't run to the bathroom very often. I'm sure this is true of other occupations as well.

[Critical1]

100# female needs a half gallon of water a day?
225# male also needs a half gallon of water a day?

that myth fails the one size fits all test right off the bat. much like the old 1 drink per hour is what your body can process (talking about booze here) when the reality is that you have to be a 250# male to burn off that much alcohol in an hour. for a smaller female its more like 3 hours

[Dunkelheit]

It's bunk in so many ways. Most fruit juices, coffee, etc., are mostly water. Consider drinking a glass of water, then put a few drops of fruit juice in another. Does the fruit juice cancel the water? Nonsense. Your body doesn't have a problem with water mixed with other things.

Besides, once it is in the stomach, it is mixed with other stuff, anyway, before being digested. You stomach doesn't keep a separate compartment for "water only."

It will, however, make a difference if you're consuming a lot of diuretics or other substances which make your kidneys remove water from your bloodstream at the same time. You might have just as much water going through your kidneys, but not as much making it from your bloodstream into your cells before being drawn back out again. Alcohol, caffeine, and sugar, among others, will make a difference in how dehydrated you might get even if you are consuming them along with water.

Personally, I know that if I'm getting the bulk of my liquid intake from tea and soda, I tend to be somewhat dehydrated no matter how much of them I drink. The abundance, colour and opacity of urine is a good indicator of whether you're getting enough water overall, as someone pointed out earlier. But it doesn't tell you whether that water is going into your cells or not first.

[isaiahrobinson]

It's bunk in so many ways. Most fruit juices, coffee, etc., are mostly water. Consider drinking a glass of water, then put a few drops of fruit juice in another. Does the fruit juice cancel the water? Nonsense. Your body doesn't have a problem with water mixed with other things.

Besides, once it is in the stomach, it is mixed with other stuff, anyway, before being digested. You stomach doesn't keep a separate compartment for "water only."

That's mostly true, but certain fluids like coffee or stronger alcohol (eg. wine) are genuinely not as hydrating as water because they have a diuretic effect.

[Musicat]

That's mostly true, but certain fluids like coffee or stronger alcohol (eg. wine) are genuinely not as hydrating as water because they have a diuretic effect.So what is the net gain or loss? Surely we can quantify it, based on caffeine or alcohol content.

[isaiahrobinson]

So what is the net gain or loss? Surely we can quantify it, based on caffeine or alcohol content.

Oh, caffeinated drinks are still a net gain - in fact some studies like these ones (http://www.nytimes.com/2008/03/04/health/nutrition/04real.html?_r=1) claim that the net gain is almost the same as water - but it's worth bearing in mind that caffeine does have a mild diuretic effect so it's not quite as good as drinking water. This study (http://www.jacn.org/content/19/5/591.full) actually claims its results show there was almost no difference in hydration between caffeinated and non-caffeinated drinks, nor any difference between calorific and non-calorific drinks, so you're definitely correct that fruit juice is just as good as water. Even coffee is probably not too far off. From personal experience I find I feel noticeably less hydrated a few hours after drinking caffeinated drinks than I am after water though.

Alcohol has a more significant effect, particularly stronger alcohol like wine or spirits, as found in these studies (http://www.water.org.uk/home/water-for-health/medical-facts/alcohol) and this study (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC438648/?page=1). Very weak beer (like 3%) is still a good net gain; I suspect spirits are a net loss. In between, I'm not sure.

[Dunkelheit]

This study (http://www.jacn.org/content/19/5/591.full) actually claims its results show there was almost no difference in hydration between caffeinated and non-caffeinated drinks, nor any difference between calorific and non-calorific drinks, so you're definitely correct that fruit juice is just as good as water. Even coffee is probably not too far off. From personal experience I find I feel noticeably less hydrated a few hours after drinking caffeinated drinks than I am after water though.


From the link: "Body weight, urine and blood assays were measured before and after each treatment." That measures the amount of water going into and out of the body as a whole, but doesn't say anything about where it goes in the meantime. Body weight measurements can't tell the difference between cellular and intercellular water, for instance. I also have to wonder what the effect of possible additional intake on the off days of the study might have been. It would be more useful if they'd been able to keep the subjects on a regimen for the whole time rather than only a couple of days per week.

I'd like to see something that measures the amount of water getting into the cells themselves before going back into the blood and to the kidneys, if that's possible. I'm sure there must be some way to measure cellular and intercellular water levels. Because there might be just as much water in the bloodstream, and hence the urine, but as you and I and others have noticed, the tissues feel dehydrated after caffeinated drinks, and especially after alcohol. Even sugary non-caffeinated drinks can have that effect in my experience, though fruit juice is less likely to do so than, say, Kool-Aid. It's not just diuretics as such that can cause that, but other chemicals as well.

[BigT]

I always thought this was touted as a weight loss method, not something about actually needing that much water. The idea is that water can help mediate between meal hunger. I admit that drinking a couple glasses of water when I'm hungry makes me not hungry. I just don't do it because I also feel sick.

[Colophon]

Besides, once it is in the stomach, it is mixed with other stuff, anyway, before being digested. You stomach doesn't keep a separate compartment for "water only."
This is all you need to tell her - if she doesn't immediately realise she's talking twaddle about "only pure water counting" then she's beyond reasoning with on this matter.

I drink maybe two glasses of water a day. The modern obsession with "hydration" is ridiculous, all it does is make you piss 20 times a day.

[KarlGauss]

I drink maybe two glasses of water a day. The modern obsession with "hydration" is ridiculous, all it does is make you piss 20 times a day.Although I tend to agree with you, there is some evidence that high water intake lessens the risk of bladder cancer (http://www.nejm.org/doi/full/10.1056/NEJM199905063401803) (as well as kidney stones (http://jasn.asnjournals.org/content/15/12/3225.abstract)).