8 Glasses of Water Myth

sarahrbraun

I'm getting really tired of all the inaccuracies around this.

I have a masters degree in hydrology with a minor in veterinary sciences and, as we all know, the human digestive tract is identical to that of 87% of domesticated animals.

Our bodies' composition in regards to water ratio stays fairly consistent and mimics that of the Earth (this can change due to season and now has been a bit erratic with global warming). In the summer, it is important to drink more water the closer you live to the equator. In winter, obviously, you would do the opposite.

Those looking to burn fat and gain lean muscle need to pay closer attention to their water intake. Anything less than 8 cups requires a 15% increase in carbohydrate consumption to store the fluid and make more efficient use of it. Between 8-12 cups will put you at the sweet spot for muscular hypertrophy, and anything over 12 cups is nearing the danger of death by downing.

I really hope this ends all the petty arguments - ignorance isn't attractive, folks.

(edited for spelling mistakes, witch also are not attractive)

so I am damn lucky I didn't DIE all the days that I drank 16-20 cups (128-160oz)? I suppose you are going to tell me that my urologist is an idiot for doing a 24hr urine collection every 6 months and telling me that I need to drink 3-4L minimum to be properly hydrated based on my labs?

nothing1994

Bump. Interesting :O

NPetrakis

I know this has been posted about a month ago, but that thread was dead empty.

The 8 glasses of water theory has been debunked. There are no studies and no evidence that shows that you need to drink 8 glasses of water a day to stay healthy.

http://www.cbc.ca/news/health/story/2012/06/08/water-eight-glasses-myth.html

That being said, I am unaware of any studies that has any evidence stating that you shouldn't drink that much.

Completely agree. I've spoken to a number of dieticians about this. They all agree. Too much water is bad, not enough is bad. Bottom line is if your fingers are shrivelled after exercising a lot you need electrolyte replacement mixed with water. How much water is good for you depends on many medical factors (heart, kidney function) etc. I know of two cases I saw personally (One a marathon runner) that replaced fluid loss with just water....and dropped their serum (blood) sodium levels so low they went into a coma (one had a seizure). So before you go drinking "tons of water" quickly.....think twice and get some professional advice.


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If you're looking to partake in severe exertion events; marathons, triathalons, etc, You need a trainer and a doctor that you can consult regularly so that you know how YOUR body responds to hydration and dehydration. The rest of us would likely never know the difference.

The danger of declaring water consumption a "myth" is acute. There are those who will take that as permission to not hydrate to their activity level and invite risk of injury. It also nicely complements the danger of having a message board in a site like MFP where people can often offer their imbecile amateur medical advice.

Ask a doctor. Not a heuristic healer, or medicine man, or medium, or YouTube guru but a real bona fide MD doctor with an office and the works. Then listen to what they say about your lab work, then train.

Good luck to all!

KatiD83

I agree! I was drinking 8-10 cups a day and was retaining the water. My trainer suggested I only drink when thirsty and I'm starting to lose the water weight. All I can say is everyone is different, some retain water more than others.

chantalM613

Your body needs to stay hydrated. Period. If ur working out then more so. If ur eating a diet full if fruits and vegs (like nine plus servings a day). Less so. If ur waiting till u feel thirsty you're too late.

Your urine should be the color of lemonade. Thats the easiest way to know if ur fluid levels are right.

Everybody feels better when they are eating healthfully and this includes getting enough fluid....pretty simple!

chantalM613

Sorry... I cant imagine a trainer telling u to drink when u feel thirsty! Also the way to get rid of water retention is to drink...?

chantalM613

Water toxicity is extremely rare. Y'all probably don't need to worry about that... especially not with only 8 cups per day.

Water needs are individualized but 8 cups is a good ballpark estimate for most people of an average weight. The Academy of Nutrition and Dietetics (and most dietitians) will recommend 1 ml water per calorie based on your daily caloric needs. For example I eat 1800 calories a day. So, 1800 ml water is appropriate. 1800 ml divided by 30 ml/oz = 60 oz, and 60 oz divided by 8 oz/cup = 7.5 cups of fluid.

Bobby_Clerici

I credit water as a huge reason I lost so much weight.
Water aids all the functions of the body, and 8 cups is more than enough, because we get some from foods and such.

First, before a meal, I drink a cup; it has no calories and fills up the stomach, making me less hungry.
Second, keeping the body properly hydrated prevents excess water retention.
And there is a bunch of folklore regarding water and metabolism - who knows?
I just know I did much better drinking a lot of water.

Health benefits of drinking water might include: [I said MIGHT]
regulate appetite
increase metabolism
boost energy levels
less water retention
alleviate some headaches
help reduce blood pressure
help reduce high cholesterol
ease joint pain
decrease in risk of some cancers
less chance developing kidney stones
release toxic waste products
improves skin

http://www.weightlossforall.com/benefits-wate r-drinking.htm

lucylAnneMason

MFP recommends 8 CUPs of water a day, not 8 glasses. 8 cups is easy to do. I always exceed that.

A glass is about 1 cup, give or take. I have some at home that are about 2 cups, others that are less than a cup. Most are pretty much 1 cup.

Nah its not, there 2 cups of water in a 50cl bottle a average glass of water is 2 cups

KatiD83

Sorry... I cant imagine a trainer telling u to drink when u feel thirsty! Also the way to get rid of water retention is to drink...?

The more I drink the more I retain. I gained 6 lbs in 5 days. I'm not highly active and I'm not out in the heat all day.

Vailara

True. You know what they call someone who only consumes water from food? ...Dead.

Or breastfed? .

We do start out getting our fluid from our food. Even formula fed babies don't tend to need much extra water. Just saying .

BeckaT79

http://www.snopes.com/medical/myths/8glasses.asp

It's a MYTH people.

If YOU believe YOU need more water - or must have 8 glasses (or cups) or think YOU need to drink instead of eat etc, that's fine.

But never tell anyone they *should* have 8 glasses of water a day.

If your Dr gives you this advice ask them what they are basing this advice on and set him/ her straight.

It's been debunked for YEARS.

Get with it.

Exactly. It's not like your body is comprised of 60% water ...er.. Ok, bad example.

It's not like your brain is comprised of 70% wat... hmm. Ok, another bad example.

It's not you'll die if you don't have enough water for more than 72 hours... oh... hmm.

Ok so, it's not like your body needs water to flash toxins and waste from your sys.... ah *kitten*...

(It's hard being this awesome.)

There is water in everything we eat. The original and WRONG calculations never took this into account - leading to the wrong advice for everyone to drink 8 glasses as the gold standard.

(It's hard educating know it alls)

A human can live up to 8 weeks without food but only live 3-5 days without water.... Seems to me you should be drinking water and not worrying about how much water is in your food source. (Seeing as though you can not calculate the proper amount). Drinking too much water is bad for you, yes I agree! It can throw off your electrolytes and in extreme circumstances lead to death. 8oz is a guideline (let me repeat that word because I think it is important GUIDELINE) if you feel you are doing fine with less, than drink less, and vice-versa. Take care of your body.

Vailara

I think the figure of 3 - 5 days survival without water has to mean without water OR anything else. I imagine somebody could survive on, say, a nutritious soup, for quite a while. I think that's what the article is saying - not that we don't need to take in any fluids, but that we can get fluids through other means than pure water. There is quite a lot of water in some foods. And most beverages will add water.

susannamarie

True. You know what they call someone who only consumes water from food? ...Dead.

Funny, I almost never drank water except when seriously exerting (as in, over 2 hrs/day exercise). As a matter of fact, for years I drank only milk and soda. Caffeine-containing soda.

Guess I'm a sign of the zombie apocalypse.

mcarter99

It does assist with weight loss though, which is what most of us are here for. Plenty of studies on that! So, drink up.

I haven't seen studies on that, except that it helps to drink more if you're dehydrated. Or if you somehow feel more full by drinking and so eat less. In studies, satiety isn't shown to be hugely affected by plain water, though. Not like it is by water in foods.

A lot of people never drink water. They drink other beverages only. They're all made of water, though.

1968neil

you can't "drown" by drinking water, unless you're submerged in it.

It is possible to drink too much and strip the body of electrolytes if the rest of the diet is imbalanced.
Otherwise, there are no negative consequences. Far less damaging is over consumption than under hydration.
Once the body enters a state of stress or trauma that is heat or water related, it may be too late to reach for another glass.

So drink and eat according to activity, and block out the noise.

you are right in effect. Drowning infers interference of the passage of oxygen across the alveolar membranes in the lungs (in its simplest terms)

And you are right that too much water can strip the body of electrolytes. This is the dangerous thing. Here is the mechanism- you drink loads of water. This enters your GI tract which has a semi-permeable membrane. This means that compounds such as electrolytes proteins sugars etc can move across the membrane in either direction from areas of high concentration to areas of low concentration. This is how nutrients get from your gut to your cells, how CO2 produced from metabolic activity enters your blood and is then passed from your blood into your lungs to be exhaled, how o2 gets from your lungs to your blood and from your blood to your cells. Its all about concentration gradients and semi permeable membranes. OK, back to water. So your stomach and GI tract has loads of fresh water in it. Your blood has a higher level of things like sodium, potassium etc dissolved in it. (Ive chosen sodium and potassium for a reason...) So this sodium (Na) and potassium (K) (amongst other things starts to move over from the area of higher concentration, ie the blood to areas of lower concentration, ie the GI tract full of fresh water. Now the point of all this... your HEART works on a principle called the SODIUM POTASSIUM PUMP. Thats the chemical process that causes the electrical polarisation and depolarisation within the heart which causes myocardial contraction. That is to say it makes your heart beat. Take too much of Na or K from your blood and you end up with cardiac arrest. Ask any med student, nurse, Doctor, or Paramedic about reversible causes of cardiac arrest. One of them is Hypo/Hyper Kalaemia (Low or high potassium) or other metabolic disturbances.


I have no answers as to how much water to drink, how much is too much or how much is not enough. Everyone's different. I just thought it would help for people to understand the mechanisms involved.

All the best

Kurt

And for those that are wondering my wee wee looks like straw, my mouth's not dry, and my skin doesn't 'tent' when I squeeze it. I guess I'm reasonably well hydrated ;-)

small_ninja

All I can say is, I never bought into the whole "you must drink 8 hours a day for optimum weight loss" thing. I usually only drink water when I'm exercising; all my other drinks are usually coffee, tea or diet soda. I tried doing the 8 cups a day thing but it just made me need to go to the bathroom every 20 minutes... I did it for a week and it didn't let up, so I decided to flag it. I'm still losing weight, and feel reasonably hydrated I guess. 8 cups a day just seems pretty excessive, and I have read some of the studies mentioned that revised this rule after taking into account the water that's in the food you eat...