Am I drinking enough water?
Finding a less clueless approach to hydration
Have you ever wondered if you’re drinking enough water?
I have this nagging suspicion that I live in a state of mild, chronic dehydration.
Which seems like a bad idea, given that water is the single largest constituent of the human body.
So finally, I decided to get to the bottom of it:
How much water is optimal for my health?
My better hydration plan
I’ll start where I finished.
I’ve learned that individuals water needs can range enormously and ‘8 cups a day’ isn’t a surefire recipe for success.
Instead, I need to assess my own needs, taking into account factors such as my age, size, body composition, physical activity and climate. I also need to pay a bit more attention, which I calibrate my water intake and reset my habits.
Where I’ve landed:
I can count on getting about 500mL of water from food each day, since my diet includes plenty of water-rich foods.
After that, I’m aiming for 3.5L of fluids daily from water and other non-alcoholic drinks. It seems like a lot, but I want to cover:
2.2L to achieve the baseline “adequate intake” of 2.7L (including food) per best available guidelines.
1.3L extra to cover physical activity, partial breastfeeding, and working in an air-conditioned environment.
I don’t need to change my coffee or tea habits for hydration — they make a positive contribution. Hip hip hooray!
Nevertheless, I’m trying to get most of my fluids from plain water, to avoid too much caffeine or calories from other drinks.
Thirst alone isn’t enough to drive me to drink enough water. This could be because I’m distracted by work and family, my thirst response is blunted by stress, poor sleep, or ageing — or all of the above.
Some tactics I’m using to help:
Track one day a week: A weekly check-in rather than constant daily measuring.
Watch urine colour and volume: It may be too much information, but noticing the colour of my pee seems highly effective in my case. Pale yellow is good, bright yellow or darker is a warning.
Stack water with habits: Drink a glass while waiting for tea to steep or while feeding the baby (thank you James Clear).
Err on the side of more hydration: I’m a long way off the risk of overhydration.
If drinking alcohol, drink extra water too.
If you’d like to know how I got here, grab your drink bottle and read on.
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How Much Water Do I Need?
Water is fundamental. It plays an integral role almost everywhere in the body.
One example I like to keep in mind: cellular health. Water maintains cell structure and enables energy production, DNA and protein synthesis, and countless biochemical reactions.
Would you rather have plump, juicy cells or raisiny ones?
There’s no universally agreed “right amount” of water for every person. Hydration is surprisingly under-researched.1
“Water intake and hydration remain under-investigated, and optimal hydration is poorly and inconsistently defined.”
Water intake is hard to study because it’s affected by so many variables — age, weight, body composition (muscle is mostly water; fat is only ~10%), health status, climate, diet, physical activity, and more.
The best science-backed guideline we have comes from the US National Academies of Science:
2.7 litres of total water daily for women
3.7 litres for men
When applying these guidelines, be aware:
They’re for adequate intake, not necessarily optimal intake for disease prevention. We’ve insufficient evidence to know what’s optimum for reducing chronic disease.
Adequate intake means confident of preventing “deleterious, primarily acute, effects of dehydration,” like metabolic and functional abnormalities”
They’re based on the median intake of American women aged 19–30 — a median is the middle and it isn’t the same thing as idea
They provide for sedentary to low-active needs
Total water includes water from all beverages and food. A diet rich in fruits and vegetables provides about 20–25% of total intake, leaving about 2.2L to get from fluids.
It Really Does Depend
On top of the general recommendations, a wide range of factors increase daily water needs.
Two of the biggest?
Level of physical activity
Environmental temperature
A highly active person in a hot climate might need six times as much water daily as a sedentary person in a cool one. So it’s a must to account for these factors when estimating our personal needs.
Pregnancy and breastfeeding also considerably bump up water needs for women.
How Much More Water for Exercise and Breastfeeding?
I was surprised how much extra hydration is recommended:
400–600mL (about 2–3 cups) for up to an hour of moderate exercise
More for higher intensity or longer duration workouts
Breastfeeding:
Fully breastfeeding: +3 cups per day
Partially breastfeeding: +1–2 cups per day
The Coffee Myth
It’s a myth that tea and coffee are dehydrating.
The mild diuretic effect of caffeine is far outweighed by their water content, making them net positive for hydration.
Love a bit of good news ☕️
Do I Need Electrolytes or Glucose in My Drinks?
For me, the answer’s no — unless I get into way more extended exercise or encounter special circumstances.
Most people get enough electrolytes and glucose through a healthy diet.
Sodium is the most important electrolyte for fluid balance (and the one most readily lost through sweat). If I felt I needed it, I’d try a pinch of salt or a sodium-specific supplement and not a sugary sports drink like Gatorade, which I am highly suspicious of.
Listening to My Body
Thirst is the body’s primary signal for hydration needs. Many people are fine to rely on thirst alone.
But as we age, our thirst response diminishes making it easier to become dehydrated. Other factors like stress, fatigue, or distractions can also blunt thirst signals.
Here are some other useful signs.
Urine colour: Pale yellow = good. Bright yellow or darker yellow = dehydration risk.
Low urine output: A strong signal (and why hospitals monitor it).
Dry mouth, fatigue, and headaches can also be clues.
No single indicator is perfect, so I’m watching for multiple signals.
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Easy win?
I’m nerdily excited that I could upgrade my health with something fundamental, free and (theoretically) easy: drinking enough water.
In practice, I’ve often struggled to live up to my water intentions.
But armed with better knowledge — and a few basic tactics — I’m hopeful this time it’ll stick.
Cheers to that.
Xx
Toni
Perrier, E., Armstrong, L., Bottin, J., Clark, W., Dolci, A., Guelinckx, I., Iroz, A., Kavouras, S., Lang, F., Lieberman, H., Melander, O., Morin, C., Seksek, I., Stookey, J., Tack, I., Vanhaecke, T., Vecchio, M., & Péronnet, F. (2020). Hydration for health hypothesis: a narrative review of supporting evidence. European Journal of Nutrition, 60, 1167 - 1180. https://doi.org/10.1007/s00394-020-02296-z.
Yes, Perrier!
Nice Toni! I started drinking a miso soup in the morning with breakfast and coffee and that has felt like a nice alternative to water.