ABC's 20/20 Myths: Eight Glasses a Day? From ABC's 20/20 Friday, April 22, 2005

Eight Glasses a Day?


It's become a national habit. Some might even call it an obsession — drinking eight glasses of water a day.

Wherever Americans go, their bottle of water goes with them. Two billion bottles were sold last year — enough water to fill a medium-size lake.






Barbara Buettner says she drinks up to 10 glasses a day.



It's as if the health and beauty world has adopted a liquid mantra: 8 by 8 — or eight 8-ounce glasses every day, for normal healthy Americans.






But how did we get here? It used to be that only the French were water crazy with their Evians and Perriers. Today, there are 74 water bottlers in the United States — even Coke and Pepsi have their own water brands.






Dr. Heinz Valtin, professor emeritus of the Dartmouth Medical School, is a leading source when it comes to water in the body, and he says this "8 x 8" idea is a myth.






"I drink about five or six glasses per day, only one of them is water," he said.






The rest he gets from liquids such as juices coffee, tea. And it may be hard to believe, but most of his fluids come from food.



"Even a slice of white bread is more than 30 percent water," he said. "It's lots of water, 80 [percent] to 90 percent in vegetables and fruits."






Valtin spent his life studying the right balance of water in our bodies. When he retired, a prestigious medical journal asked him to find out if there really is a fountain of youth in eight glasses of water a day.



"What's wrong with the myth is that the recommendation is universal that every last one of us, including as one article said, couch potatoes, must drink at least eight, 8-ounce glasses per day," he said.



The Institute of Medicine's food and nutrition board agrees with Valtin. It says drinking eight glasses of water is not necessary, because we get plenty of fluid from our food. When our body warns us through thirst that it's time to drink something — then drink up.

Ummmm yeah.

When you feel thirsty you are ALREADY dehydrated.

And there is nothing wrong with drinking eight glasses of water a day. This is a beneficial new habit of the North American diet, and I don't see how articles such as this are going to be of positive reinforcement for anyone.

People could probably live healthfully without exercising either, but there isn't a reason to discourage exercise either!

Right! Should anyone take medical advice from someone who sees white bread as an acceptable source of fluids?

I agree with the article. There was no science behind the 8x8 recommendation.

You are not dehydrated when you first feel thirst. You are not necessarily fully hydrated, but that is different than being dehydrated. Just like feeling hungry does not mean that you are starving.

The USA Track and Field organization has changed their water recommendations from drinking before you are thirsty to drink when you get thirsty. http://www.usatf.org/news/showRelea...003-04-19-2.xml

I'm in the middle of the road on this issue. The part of me that believes its a myth about needing the 64 oz's a day wonders how mankind has survived all these years without THAT MUCH WATER DAILY. Honestly, I can't stand the stuff...but I drink it because I assume....its what I need to do to keep myself healthy, and to get rid of my fat ass.

I try to drink 8 glasses a day, however I do count my coffee and diet sodas in that count. Otherwise I think I'd spend the day in the bathroom

Victoria

I think the water thing might be another big hype, just like saturated fat and cholesterol. Sure, it "makes sense" that all that water should do wonders for you, but it also made sense that "fat makes you fat" once. I do drink alot of water in the summer when I'm thirstier, but in the winter when I'm not very active lots of water just makes me feel bloated and slightly ill. When I fought forest fires in Washington years ago, they told us that if we didn't pee once every two hours we weren't drinking enough, which was probably pretty good advice especially taking into account the intense heat, dryness, and physical exertion. But for every day routine, I just examinethe color after I go, and if it's really yellow I will chug a 16 ouncer of water, and within twenty minutes I'm racing back to the pot. If it's clear or slightly yellow I consider I'm fine.

I dropped the water chugging habit about six months into low-carbing. I started listening to my body instead. Forcing water down and spending half my life running to the loo or planning outings around being near one just seemed plain ridiculous to me. I think that phrase “when you feel thirsty you’re already dehydrated” is one of those comments that was probably uttered by a nutritionist and has taken on a life of it’s own, much like “a calorie is a calorie” and “eat whole grains”….no actual science behind it. I drink 7-8 cups of fluid per day (when I feel like it) made up of green tea, black coffee, water and wine and have never felt better.

I think the article was just posted as a point of interest. There's no need to get hostile about it I do agree though, that there is too much emphasis on drinking tons of water. Drink a nice big glass with each meal and one or two throughout the day and you'll be nicely hydrated!

I have never subscribed to the idea of taking 8 glasses of water daily but I recognise that if one has a kidney infection then this amount may be appropriate. In colder climates one's body requires little water while in hotter climates there is a greater demand so geography looks like a feature of the amount that is required. Personally, I take about 8 glasses of liquid daily, possibly more, but it is in the form of beverages. Seldom do I find the need to drink water and I am unaware of any health problems this might have created.

I had to laugh when I heard about this. In Dr. Atkins original book (1972) he addressed fluid intake:

"Drink as much water or calorie-free beverages as thirst requires. Don't restrict fluids . . . but it is not necessary to force them either."

The good doctor had so much knowledge. I'm often sorry that he isn't still around to share it with us.

you know, it's kind of funny because the bottled water companies are making tons of money while we are all trying to get in our 8 glasses. they are making sure we think we need at least that much and laughing all the way to the bank!

I think the water depends on what you are doing. My aunt who was healthy died of a heat exhaustion after she was done mowing her lawn. She was sitting in her chair with a gatorade next to her on the table. She was only 35. In cases like that, you don't know you are thirsty until it is too late and they say if you are in the sun - keep drinking water.

I say if you are thirsty, just drink. Differing activity levels and metabolisms render any generic recommendations in this area totally useless.

Personally, though, 64 oz would be much less than I consume on any given day. It was that way before lc and even more so now. Last summer there were days when I drank about 2 gallons of water per day, and that was without forcing any at all.

Another myth, which was addressed by Dr. Valtin but not quoted in this rather skimpy summary of his work.

We're trying to unlearn the bad habit of eating more than we need and replacing it with drinking vastly more than we need? And already its leading to people dropping dead of consuming too much water during sporting events. Yikes! What a culture of "if a little is good, then vast quantities must be great!" we have.