We take this advice as a given.
In fact, I never stopped to question the origins myself. Until recently, that is.
It’s this idea that each of us need eight 8 ounce glasses of water each day to thrive.
In a sea of confusing nutritional information, you’re probably pretty confident that drinking lots of water is something we should all be doing.
Even your great aunt Bessie would tell you that without this life-giving water we’d wither up, die and turn into a pile of dust waiting to be blown away by the next breeze. Right? Tweet this.
Well, perhaps not!
Contradictory Evidence From the Sahara
In 1976 anthropologist Claude Paque published a fascinating paper on the water consumption of Saharan nomads.
These tribal folk drank very little water, yet they lived in one of the world’s hottest regions.
In fact, they drank half what Europeans living in the same environment did.
Obviously, I’m not recommending you follow the nomad’s pattern, but it’s interesting that even in such a harsh environment, the consumption of water can be minimal.
So why is it we continue to insist drinking large volumes of water each day is necessary?
Water is Needed for Survival
There are many cited reasons for drinking more water. And, a lot of them are indeed true.
But the fact is, health authorities have latched on to this notion of drinking large volumes of water for health without any substantial evidence to support it (see here).
Yep, that’s right, there is absolutely no scientific evidence that you need to drink 8 cups of water each day.
So where did this advice originate?
In 1945 the US Food and Nutrition Board of the National Research Council said,
A suitable allowance for adults is 2.5 liters daily in most instances. Most of this quantity is contained in prepared foods.
It seems that last sentence got completely ignored, doesn’t it?
Dr Margaret McCartney wrote a commentary for the British Medical Journal in 2011, which argued the advice to drink 8 glasses of water a day is,
Not only nonsense, but is thoroughly debunked nonsense.
Dr McCartney suggests it is bottled water companies who have perpetuated this myth still further, in order to gain financially.
She points to one campaign, Hydration for Health, with the aim of encouraging people to drink more water.
However, this campaign was sponsored and created by French food giant Danone who produce Volvic, Evian, and Badoit bottled waters.
So we don’t need to drink lots of water after all then?
Not so fast!
Regardless of the origins of this advice, most people do, in fact, need to drink more water each day.
My query is not whether water is necessary for good health— it most certainly is — but whether each of us need specifically eight glasses, as most believe.
In truth, drinking eight 8 ounce glasses of water each day is unlikely to cause any harm.
But, it’s unlikely that eight is some magic number either.
Make Water Your Drink of Choice
While most people would benefit from making water their primary source of fluid, one constantly repeated myth is that you cannot count caffeinated drinks, like coffee and tea, as part of your fluid intake because they have a diuretic that will dehydrate you even further.
This is untrue.
Fluid is fluid, no matter where it comes from.
It’s obvious there are better sources, though, and water is one of them, but I want you to make your choices based on truth, not some myth that has been repeated so long and loud that no-one even thinks to question it.
Listen to Your Body
Just like there’s no need to count calories, there’s no need to count your fluid intake.
The key is to listen to your body, and trust it to guide you on how much fluid you need to take in each day.
Never forget how amazing the human body is at letting you know what it needs… if you pay attention!
Let me explain…
If you lose between one to two percent total water from the body, your thirst mechanism will kick in to let you know that it’s time to drink something.
I’ve heard it said over and over again that once you feel thirsty it’s too late you’re already dehydrated. However, that is also nonsense.
The body uses thirst to guide us on how much water we need to drink, making sure individual needs are met as a result.
Think about those other bodily functions you do without very little effort of thought.
You don’t have to calculate how much air you’re going to breathe in each day, or how many times you should blink, your body does all of the thinking for you.
Likewise, it shouldn’t be any different for drinking water (or eating, in fact!).
Don’t Drink too Much
Lots of people are in the habit of guzzling down heaps of water each day. But, that’s not a good idea either.
If you drink a large quantity of water in a very short time, it will not be utilized efficiently by your body.
This is because the water does not get a chance to reach the extracellular space where it is needed, meaning it will have very little effect on your hydration levels.
The only thing it does is dilute the urine, and make you run to the bathroom.
Aim For Light-Colored Urine
Another way to be sure you’re getting enough to drink, is to check the color of your urine.
You want it to be a light-colored yellow, but not too pale either.
If it is dark yellow, though, you are not getting enough to drink.
Water is Not the Only Source of Hydration
Don’t forget you will also be getting fluids from fresh fruits, vegetables, meats, eggs, dairy, and others foods, too.
Pretty much every time you eat, you get some water, too. Most people don’t think to count this.
Highly nutritious fluids are another great way to hydrate your body and get a nutrient boost at the same time.
These include milk, vegetable juices, and fermented drinks, like kombucha or milk kefir.
This is partly because of the high water content of fruits and vegetables, but also because they contain salts, natural sugars, and nutrients.
Researchers suggest fruits and vegetables can be are more hydrating than water, because they replace the fluid lost with one that is similar to the body’s natural composition, therefore hydrating more effectively than water alone.
So, how much water should you drink?
It’s clear the advice to get eight 8 ounce glasses each day is nothing more than a guideline.
It’s a sweeping generalization that may not be the best advice to meet your specific needs.
So, instead of trying to meet a defined level each day, try following your own thirst instead, and trust it to tell you when you need to drink more.
Aim to become more aware of how much fluid you are taking in from both drinks and foods, and how you feel when you are well hydrated or dehydrated.
Make sure your urine has a pale yellow color to it, and that you only have to urinate once every few hours.
If you follow these simple guidelines, you will naturally meet your body’s hydration needs without too much effort.
Do you drink water regularly? And, do you count the amount of water you drink, or leave it to chance?
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