The old notion of having to drink 6-8 glasses of water a day is actually a myth. This amount (about 2.5 liters) came from a half-century old study with no basis in fact. The truth is that we do lose some water to bodily processes like breathing, sweating, and urinating, but not that much. Although over-consumption is not necessarily a bad thing, as a rule of thumb, people should simply drink water when they are thirsty, and don’t when they are not.

Key Takeaways:

• Due to basic physiological functions, humans naturally lose water and fluids throughout the day.
• All of our foods have water in it, so your body’s job is to let you know when you actually need water by telling you that you’re thirsty.
• Drinking more water than you actually need is dangerous and poses numerous health problems.

“Over the course of the day, we lose some water as water vapour from our breath and some water is lost through sweat.”

Read more: https://www.mcgill.ca/oss/article/health-nutrition/water-myth