Water is THE most essential nutrient in our diet and so we need more of it than any other nutrient. After all, over 50% of our body is water! It makes up ~50% of our blood, 70% of our muscles and about 75% of the brain – wow!

Exactly just how much water do we need?

Here are the recommendations for daily water intake. It seems like a lot but if you are vigilant about drinking water throughout the day, it adds up quickly.

  • Men (aged 19-50 years): approx. 3.7L total water per day
    (approx. 3.0L from food/beverages)
  • Women (aged 19-50 years): approx. 2.7L total water per day (approx. 2.2L from food/beverages)

You must be crazy! That seems like an impossibly high number! How do we get all that fluid in our body??

We gain fluid:

  • By eating and drinking
  • Through our body’s metabolic reactions

We lose fluid:

  • Through urine, feces, skin (sweat), lungs
  • Illness (fever, coughing, vomiting, diarrhea, runny nose)
  • Blood loss
  • Exercise
  • Pregnancy and breastfeeding
  • Consumption of diuretics (alcohol, coffee, tea, pop, some medications)
  • An increase in dietary fibre, salt or protein
  • We also lose fluid in forced-air environments, like airplanes

So what happens if we don’t get enough fluid?

This is called DEHYDRATION. Infants are particularly at risk because they have higher fluid requirements and can’t express their thirst. The elderly are also at risk because their thirst mechanism is less sensitive, therefore they don’t drink as much.

Symptoms of Dehydration in Adults:

  • Thirsty
  • Light-headed
  • Less frequent urination
  • Dark-colored urine
  • Fatigue
  • Dry skin

Symptoms of Dehydration in Children:

  • Dry mouth and tongue
  • No wet diapers for 3 hours or more
  • No tears when crying
  • Skin doesn’t flatten when pinched and released
  • High fever
  • Irritable or listless
  • Sunken abdomen, eyes or cheeks

How can I increase my fluid intake?

  • First and foremost is to DRINK WATER! Buy a reusable water bottle (BPA-free!) and carry it with you all day. My water bottle is 700mL, so I know if I drink at least 3 full bottles of water a day I’m doing good. Set little deadlines for yourself, like to have one bottle drank by 11am, another by 2 etc, or maybe tell yourself you have to drink one glass of water before each meal On days when I’m on campus I try and say, okay I need to drink at least half this bottle by the time class ends and start another bottle after my break, something like that. It really does help!
  • Eat watery foods (especially fruits and vegetables – they are made of mostly water!)
  • Eat low-sodium soups
  • Drink juice or milk or NON-caffeinated or carbonated beverages or alcohol (these are dehydrating!)

Water not only keeps your internal body hydrated, it also hydrates your skin. (That’s why we get dry skin when we’re dehydrated!) Water also helps to flush out any toxins that may be in your body, aids in digestion and keeps your bowels moving to avoid constipation. Water can also help fill you up. If you’re hungry after you’ve already had your afternoon snack, try having a glass of water. It’s a glass full of zero-calories, that will help you feel full while doing all kinds of good things for your body!

There’s a lot of talk about whether the “8 cups of water a day” is accurate or not. From what I’ve comes across so far, it seems to be. 1 cup is equal to 250mL, so 8 cups is equal to 2000mL, or 2L. This matches the recommendations at the top of this page. Personally, I can always tell at the end of the day whether I’ve had enough water. I just all around feel better you know? I think the more water we can get in a day, the better. It has so many benefits that we really can’t go wrong with a big cold glass of H2O. Start guzzlin’!

Read about the other nutrients we need to live: carbohydratesproteins, fatsvitamins and minerals!

10 thoughts

  1. Thank you for this post, AND for the comparison of liters to cups (I was just about to look that up, lol). I am considerably overweight currently, though I’ve always eaten “healthier” than most people I know, and have been finding it very challenging to correct the problem. So I have been reading a number of different approaches to solving my tendency to put weight on so easily, and one approach looks at the effect of a clogged lymph system. And the 3-day “fix” for that includes drinking half your body weight in ounces of pure water a day (which sort of makes sense now that I know we are “50% water”)!

    Needless to say, I couldn’t imagine drinking 16 cups a day, when I normally can barely get down 4-6! (I guess I’m one of those “elderly” with a “less sensitive thirst mechanism”). But I am here to report it is not only do-able, but I can actually feel the benefit from it already in only 5 days (okay, yesterday I only remembered to drink 12 cups :-)!

    What I do is set a timer to go off every hour, from roughly 6 am to 9 pm, at which times I drink 1 cup (and also stretch & move a little, if I’ve been sitting). If I miss one, then catch up involves having a cup every half hour until I’m back on track. And in just these few days (5), one of the desired benefits I’ve already noticed is that the perpetual swelling in my feet is much, much reduced!! So I can definitely attest personally to the value of increasing ones intake of water, and am so very glad that I finally appreciate its importance.

    Now if only I can become as diligent about getting enough sleep! But I may be able to report another completely unexpected benefit from the water, which seems to be psychological in nature. It may be my imagination, but I think I am more aware now of when I’m feeling sleepy and becoming less resistant to going to bed at those times (although, of course, with all that water, I am still having to get up at least once a night for you know what ;-).

    If you are interested, I’m happy to report back whether all this water is actually helping with the weight gain/loss as well! But I’m also going to be exploring other approaches at the same time: gut bacteria (#1) and hormone balancing, speeding metabolism, etc. And getting rid of my “wheat belly,” lol! One or more of these approaches is BOUND to do the trick – IF I can manage to stay faithful to their principals while living with a carboholic daughter and 9 yr-old granddaughter, that is!

    Thanks again for sharing – and listening. 😀

  2. Question: the author of the clogged lymph “fix” that includes so much water says not to count any water intake that has lemon or other fruit juice, coffee or tea in it. can you think of any reason for that? The only thing I can come up with is that she assumes if there is lemon or tea, there is sweetener? I drink 2 cups of warm lemon water upon arising, with powdered Vit c, 1 Tbsp psyllium seed, and a few drops of Stevia in it (for years almost the only water I drank!). I’d like to be able to include that in my daily count. What do you think? Any help you can offer will be greatly appreciated!

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