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Is 8 Glasses of Water Per Day Overkill?
An anonymous reader writes: "David Harris reports in his science news that the American Journal of Physiology today published a study dispelling the 8x8 myth. That is, the recommendation to drink 8 eight-ounce glasses of water per day has no scientific evidence behind it. The paper also mentions the risks of drinking too much water and explodes some other urban myths of water drinking such as the 'thirsty means dehydrated' and 'dark urine means dehydrated' myths."
hahahaha. CLiT continues to DIE thanks to CmdrTaco. hahahaha
special recognition for first CLiT is Dying post.
Sincerely yours, The Water Baron
Have you ever tried drinking 8 glasses of water? You feel all bloated and can hardly move, and the first place you go is to the closest washroom to feed the sewers.
For once, the /. article summary says nearly as much as the linked-to articles themselves. It's funny, no matter how hard I try to challenge preconceived notions I have, there's always one more "well-known fact" I forget to look into.
The part about water in caffeine drinks counting towards you're recommended intake struck me as most contrary to my own anecdotal expereience--it seems like whenever I drink anything caffeinated, I'm thirsty for water shortly afterwards. I suppose this discrepancy is either in my head, a bizarre artifact of my own physiology, or a misinterpretation of the abstract linked to here.
It pisses me off that i can't read this without paying. I mean all were getting here is the watered down abstract. And the link will likely be hosed shortly anyway due to ./ effect.
I always thought it was cans of Coke!
I might have to re-evaluate my daily drinking.
no sig.
lets see, i drink about 3 cans of soda, 12 ounces each, since the first ingrediant is water id say about 8 to 10 ounces of the soda is water... so thats 3 of my eight, for dinner i drink water or something, probably another 2... so thats five, and probably about eight ounces for breakfast, damn thats 2 left. And even with 2 left i consider myself well hydrated... hmmm maybe eight is too much.
I think this paper is clear evidence that we all need to drink more Bawls. :)
Learn to Play Go
Yup. NPR had a story with the author of this study this morning, quite interesting too...
Guest host Renee Montagne talks with Dr. Heinz Valtin, doctor of physiology and professor emeritus at Dartmouth College, about a new study saying that people may NOT need to drink eight cups of water a day to stay healthy.
story on npr.org
Lets hope they got over the deep linking craop.
.....
Not a Sop to Drink (February 6, 2001)
Water - the myth of 8 glasses (February 13, 2001)
How much water do we really need? (May 24, 2002)
Do the Physiologists have amazingly deep databases, or is something funny going on here?
Drinking water is good for you. Drink lots of water. When it is hot, humid, and I am outside, I can drink that 64 oz of water within an hour or less. The people who don't drink enough water get taken away in an ambulance.
You are orders of magnitude more likely to experience dehydration than to experience the almost mythical "water intoxication." (Yes, it is possible to kill yourself by drinking too much water, but it happens very very rarely.)
So ignore this article and go have a nice glass of water.
Tim
Omnia vestra castrorum habetur nobis.
You doctors have been telling us to drink eight glasses of gravy a day!
Y2K Compliant since the late 1890s
I used to drink about six cans of Diet Coke a day, plus one Diet Coke from the soda fountain at lunch.
A friend I respected suggested that I consider drinking more water and less soda. He claimed that I would lose weight (I was 265 pounds at the time) and feel better.
What I discovered is that I did lose weight, although not enough to significantly impact my appearance, but more to the point I felt better - I was generally more alert in the afternoons, and after a while just a few sips of a Diet Coke would give me more energy (when I needed it) than a whole one would previously.
It looks like caffinee becomes steadily less effective as more of it is used, so the simply exponent of abstaining from it and limiting its intake worked well.
So I would recommend something like this to anyone trying to become more healthy. I started losing weight at a good clip, incidentally, when my new job responsibilities made me less sedentary. Annoying but good for me in the long term.
D
I'm feeling a bit drained....
* And remember, it's spelled N-e-t-s-c-a-p-e, but it's pronounced "Mozilla."
Now, if this was an article reporting on a study that followed the general health and well-being of a number of participants over a certain period of time, relating health to water consumption, with a control group given a placebo of, say, Mr. Pibb or something, then I would be a bit more inclined to read on beyond the abstract.
If literature reviews get you a publication in the Journal of Physiology and a spot on NPR, then I think I'm in the wrong line of academic inquiry.
Roll on tenure!
MEEP! MEEP!
What no one seems to have mentioned is that caffiene is said to be a dieretic (sp??). That is, it acts to dehydrate you and make you loose more of the water you are consuming. This is usually one basis of the argument that you need to drink water and not caffeine loaded drinks.
:-)
Another is that when you don't drink enough pure water, your body notes the lack of water and when it does get pure water it stores it as body fat so that the body has a supply to call on when it really needs it given its belief that it is in short supply.
The argument then is that if you drinks lots of water, your body sees it always has access to a good supply and doesn't see the need to store it. This possibly being why people who drink lots of water and not caffiene drinks tend to be slimmer.
Obviously, if you put the weight on because of caffiene drinks and go back to just water, a bit of exercise would probably help as well, otherwise the body has no way to burn off all that fat you have accumulated.
BTW, it is sometimes said that people who smoke tend to be thinner as well and when they give up smoking they gain weight. Thus, someone who smokes and is also a caffiene addict might have the right balance.
It's recommended that people taking certain recreational pharmaceuticals put a limit on their water consumption, since some have an anti-diuretic effect.
You can get water from sources other than just a glass of water - for instance, all those servings of fruit you never eat.
(Disclaimer: I am not a doctor)
The whole 64 oz per day thing is a bit off, but here's why: water intake should actually be proportionate to body weight, but a surplus isn't necessarily a bad thing. Increase per caffeine intake (diuretic effect counteraction) and per physical activity increase (like Camelbak says, "hydrate or die").
For instance, if a 150 lb random were to drink 64 oz of water over the course of 1 day and spend the day sitting in front of his computer, they would be well hydrated and urinating fairly frequently as a side effect. (They would be lethargic due to caffeine withdrawal, but they would be very well hydrated.) If the same 150 lb random ran a marathon and only consumed said .5 gallons of water over the course of the run, they'd be cramping from heat exhaustion by mile 24. (Seen it.)
Now take a 300 lb random. If they spent the day in front of the computer and gave them 1/2 gallon of water to drink over the day, they'd be particularly thirsty to the point where they would feel dry. Increase the water intake and they'll feel better. And if your random is running a marathon, that 300 lbs better be muscle lest he wear himself out despite proper hydration.
(end disclaimer section)
More data can be found by doing a google search, natch.
This sig no verb.
had best get with the program. Eight glasses of water a day is obscene, especially with the way you people wear a stillsuit.
Use it on the field!! h2O...gaatoraade...h2oooh...water sucks, it really really sucks ------ now that's some high quality h2O ------ courtesy of the waterboy..come get me MPAA!!!
1) It is true that 8 glasses of water need not be drunk each day. It *is* true that the equivalent, two liters of fluid, must be consumed -- but food contains 30-50% of the water you need each day.
2) It is true that "being thirsty means you're already dehydrated" is an exaggeration, but it is an intentional one. It means "you're well on the way to being dehyrated". The exaggeration is, I suppose, intended to catch ID10Ts who ignore thirst even during 10-km runs in 110 degree weather. Thirst does kick in well after you have lost plenty of fluid, and once ADH (anti-diuretic hormone, the hormone that controls urine production and volume status) has already risen. These facts, I suppose, are the origin of the common anecdote.
3) "Dark urine doesn't mean you are dehydrated" -- not true. It *is* true that it is difficult to judge from color alone. Despite our 16 million color resolution, it is hard for people to subjectively grade color without experience (i.e. working in a urinalysis lab); thus, judging hydration by urine color alone will have a high error rate and often be inconclusive. Other factors, such as urine contaminants, might make the test less accurate. Along with other clues, however (i.e., being sweaty, thirsty, and tired), it may be useful.
4) "Water intoxication", a peculiar form of hyponatremia (low blood sodium concentration), is *not* mythical. However, it *is* much rarer than dehydration. It takes a special kind of person (read: mentally ill patient) to drink the 25+ glasses of water per day that it requires to achieve this.
5) Studies have shown (sorry, I don't have links, its 0130 around here) that caffinated beverages such as Coke hydrate at about 2/3 the rate of pure water. That is, at Coke concentrations, the caffeine dose is sufficient to cause you to lose 1/3 of the water you just drank as part of the Coke.
6) These indicators -- thirst and dark urine -- are not "myths" and not useless (although they are far from perfect). I happen to know first-hand that some of the best doctors in the United States use these observations in their daily assessments of patients.
7) "Absence of evidence is not equal to evidence of absence." --paraphrased from Carl Sagan
This fellow has done very little experimentation on his own, but simply collected the lack of research combined with evidence from his own student experiments over the years. While this is a provocative article, it is intended to stimulate research, and NOT to be the definitive work on the subject. What's needed (as he states at the end, in A CALL FOR DIALOGUE) is more and better (and better funded, pretty please)nutritional research!
Disclaimer: IANAD (but I am in medical school and work with 'em in hospitals every day; see address.) And yes, I am a geek. Been programmin' since age four (BASIC on a c64), researchin' at MIT. Good enough for youz?
Your friendly neighborhood nitpicker
I live in Santa Fe, New Mexico. It's a high desert region; the altitude is seven thousand feet and we get about a dozen inches of rain this year.
If you don't want to get seriously sick here, you must drink mass quantities of water. My first visit to New Mexico was a hiking trip I took when I was fourteen. The rangers recommended eight liters of water a day, which probably was overkill--but not by so much as one of my companions thought, who ended up spending a night with some pretty bad nausea from the altitude and lack of humidity.
It's true that you might not need quite so much in less extreme climates, but it's a great deal harder to give yourself water intoxication than to get dehydrated. Besides, it gives you an excuse to get away from that accursed keyboard.
everyones body is different. you should only need to drink as much as it takes for you to start peeing white.
forget the 8 glasses a day thing. listen to your own body talk.
-- Betting on the survival of the media industry is a serious risk. I advise investing elsewhere.
After this story, and one yesterday aboutt he size of drinks cups also in ounces, I've looked up the conversion rates to see what you're all talking about
from this web site :
1 American fluid ounce = 29.57 millilitres.
1 British fluid ounce = 28.41 millilitres
So the American 8oz cup is just under a quarter litre (or around halfway between a 1/3 and a 1/2 English pint, if that's more your kind of reference size....)
5) Studies have shown... ...
6) I happen to know first-hand
Sorry, No, these kinds of statements are not ever 'good enough' and never will be. If you don't have proof available, keep your authority-loving opinions to yourself. I dearly hope you are never the doctor of any of my friends or family.
As one who suffers from somewhat-chronic kidney stones, I'll say this: Drink lots of water.
If any blood relative of yours has ever had kidney stones, you may be suseptible -- and since its possibly the most painful ailment that you can be afflicted with (even more painful than childbirth) -- you'll want to avoid having them at all costs. The best way to avoid these horrible little bastards is to drink as much water as possible. I try to drink ten glasses a day (but most days, I only drink 2 quarts).
--AnonOn a low-consumption day I may drink as _little_ as eight glasses of water. On a typcial day I drink in excess of 4 litres of water (more than a US Gallon for the metric impaired).
On really hot days, and on my wight training days I can easily down 12 litres of water.
The article referncend cites a disadvantage or problem in frequent bathroom breaks. I personally NEED the breaks as the bathroom is 500m from my desk. (resulting in tracking 8km of walking per day).
The old saying tht `Americans think 100 years is a long time while Europeans think 100 miles is a long way' is clearly true.
I can walk 100 miles within four days. Ten bucks says I'm not going to live 100 years, and most of you won't either. This is why life + 70 year sentences are too long.
Will I retire or break 10K?
1) How about some references for this, other than just your word?
2) Depending on how one quibbles over the meaning of dehydrated and thirsty, various correlations can be supported.
3) In other words, there are so many variables and exceptions, that dark urine doesn't mean you are dehydrated.
4) In other news, eating 25 pounds of food at one sitting can be hazardous to your health.
5) Further revelations show that alcohol is also a diuretic.
6) Certain myths are not myths as long as you account for the 1001 exceptions and variations that make them hard to pin down.
7) Just because you didn't cite any references other than your self-proclaimed "medical-geekness" doesn't mean there are no references, therefore we should trust you.
And just how much experimentation on your own have YOU done as a medical student?
Nope, not good enough for me. Go exhibit your ego elsewhere.
Infuriate left and right
What the hell are you all talking about? Oz, lb, pint, inch, mile... In every other post I find another weird unit of measurement. I would have thought that geeks would be the first to adopt the metric system! And when I thought I finally saw a friendly unit - a "degree" for temperature - well, somebody claimed it was ten degrees hotter than water's boiling point. Oh well, I should have expected that - a different degree, of course. :-(
When I found out that PSI means "Pounds per Square Inch", I could have laughed my ass off. The conversion to Pascals (kg/m^2) isn't even linear...
drinking too much water ... explodes
:O
So that's what happens! Guess I'm not thirsty now.
-Ed
docbrown.net
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Ed Wedig
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docbrown.net
I just wanted to express my exasperation at the two negative replies to your post - don't listen to them! If only I had mod points...
------------------------------------
Spiral out... keep going.
I agree with your assessment that 64 oz. of water is not optimal for different body weights and activity levels. Instead, I use this formula:
(body weight in ounces) / 2
The formula gives you a more optimal amount of water for your weight. For example, a 150-pound man would drink 75 ounces of water per day. Adjust the number based on your activity level.
Also, you should drink the water gradually throughout the day. Drinkin a bunch of water all at once won't help you that much. Your kidneys will just remove the excess water from your system to maintain osmolarity and plasma levels.
You're a crock. Er, sorry, moron. Yes, moron. Or crock of shit. Or sack of shit, rather. Hard keeping all this straight. Hell, you probably think eating several servings of fruits and vegetables a day is a crock, too. Jackass.
I drink at minimum 4 liters of water a day (hell, just that much on the way to and at work). And since I started doing it, I really fell much better, and I think more clearly.
8x8 may still be a good idea, but relieving yourself from all that water is just as important.
Trolls lurk everywhere. Mod them down.