Just saw one of those articles about “you should drink 2 litres of water a day if you’re a woman, 3 litres if you’re a man”. Amazing to see this debunked bit of misinterpretation of hydration needs is still around! How much water should you drink? Short answer: if you pee is clear rather than yellow by dinner time, you’ve had enough water for the day.
How did people latch on to the ridiculous idea you should drink so much water every day?
Well, for one the myth ignores the fact that most food includes a fair amount of water content which makes a big percentage of daily water intake. If you eat juicy delicious fruit all day long and nothing else, you’ve likely gotten enough water that way to meet your daily intake needs.
Kidney specialists do agree on one thing, however: that the 8-by-8 rule is a gross overestimate of any required minimum. To replace daily losses of water, an average-sized adult with healthy kidneys sitting in a temperate climate needs no more than one liter of fluid, according to Jurgen Schnermann, a kidney physiologist at the National Institutes of Health.
One liter is the equivalent of about four 8-ounce glasses. According to most estimates, that’s roughly the amount of water most Americans get in solid food. In short, though doctors don’t recommend it, many of us could cover our bare-minimum daily water needs without drinking anything during the day.
For another, it’s just one of those easy catch-phrase like rules of thumb people like to distill complicated issues down into, like “eat a complete breakfast every day or YOU’LL DIE HORRIBLY, IN PAIN AND TORMENT!” True for some of the people, some of the time, under specific conditions – but not a truism by any means, and can actually be counterproductive as intermittent fasting studies show.
Personally, if I drank 3 litres of water every day I’d be spending all the time I wasn’t chugging water just peeing it straight out again as my body desperately tried to get rid of all this extra fluid. Or if I was female, maybe just retaining it all and swelling so far out of my shoes I’d be dragging my ankles behind me on the ground.
The upshot is, as usual: learn new things but take them with a grain of salt a hefty dose of corroborating evidence, but most importantly listen to your body’s needs and observe how it reacts to new things you try. Just because some incredibly general rule of thumb is the most popular health meme of the moment doesn’t mean that you are it’s idealized case. You are the best authority you have on what’s good for you and your health, just by listening to your body and observing how it reacts.