How Much Water Should You Drink Per Day?

Maintaining water balance is essential for our survival.

For this reason, our body has some intricate mechanisms for regulating when and how much we drink.

When our total water content goes below a certain level, thirst kicks in. This is controlled by mechanisms similar to things like breathing… we don’t need to consciously think about it.

For most there probably isn’t any need to worry about water intake at all… the thirst instinct is very reliable and has managed to keep us humans alive for a very long time.

Then there's also the benefits of staying hydrated for optimal physical and mental function, bowel habits and maybe even for weight loss. This could be why there are recommendations to have eight 8-ounce glasses of water per day.

Interestingly, there really is no actual science behind the 8×8 rule though.

This study found it's completely arbitrary, and it really depends on the individual person. That being said, the author does emphasize that certain circumstances may call for increased water intake, more than simple thirst commands.

Water need is increased during breastfeeding, as well as several disease states like vomiting and diarrhea.

Older people may need to consciously watch their water intake too, because it seems that the thirst mechanisms can start to malfunction in old age.

Then of course we also need more during times of increased sweating, like exercise or hot weather.

Additionally I thought it's worth mentioning that plain water is not the only thing that contributes to fluid balance. Other drinks, including tea and coffee, and even foods can all influence and increase hydration status.

At the end of the day, no one can tell you exactly how much water you need.

Do some self experimentation… some people may function better with more water than usual, while for others it only causes the inconvenience of more frequent trips to the bathroom.

If you want to keep things simple (always a good idea), then these guidelines should apply to 90% of people, and they are very similar to our guidelines for how many meals you should eat per day:

When thirsty, drink.
When not thirsty anymore, stop.
During high heat and exercise, drink more to compensate for the lost fluids.
That’s it.

Follow Authority Nutrition:

Studies mentioned:

Oh! A fresh air of sanity on this water idiocy! THANK YOU!

[jeffwolf]

i had entire large intestine removed 15+ years ago from crohns and thats when i learned that that part of our bodies takes 80% of the water out bodies need. with that said in summer i drink close to 4 gals a day and 2 in the winter. i have to make up for the loss of intestine . it also means many more pee breaks and the worst was 50 times a day sitting on toilet. and then the absolute worst is not siting from blockage for 5 days.. both suck beyond words but not going was far more painful and a 15 hrs at ER was needed too.

[daimay]

Love these video, amazing channel, I can't wait to watch the next one. British accent is also really enjoyable to me 👌

[whostolemysocks]

We should drink when we want to drink because we have survived like thet for millions of years like you dont see animals drinking water all the time!!

[FFFL]

can you please do a video on "detox" Ive been looking to heal my psoriasis through diet and seen the most success on a ketogenic diet, quite rapidly in fact. However the raw food/HCLF movement stresses that I need to detox and that's why the inital effects of the diet are so negative. This seems a little shady to me, and I would love to hear your opinion on it!

[adil]

bro i drink 4 liters per day and im from hot place did this ok ??