Today's post is a continuation in the series of posts I'm writing based on the November 2016 issue of Scientific American in which a feature article focuses on "Things We Know to Be True". This issue only had a single sentence statement on the question in the subject of this post, but it is one that covers a very common misconception related to one's health.
How much water should you drink each day? It's very commonly stated that humans need eight eight-ounce glasses of water (or other liquid) per day. That's 64 ounces of water per day. Unfortunately there is no science to back up this claim. Obviously we need water to survive and can't survive more than a couple of days without water. But do we really need 64 ounces? Drinking too much water can kill you too!
There is no specific amount of water or other liquid an individual should drink each day. The Mayo Clinic states this depends on many factors, such as age, health, and physical activity to name just a few. The best rule of thumb to determine how much liquid to drink is to drink when you are thirsty and don't drink when you are not thirsty. Your body is the best indicator of how much you should drink. Your body will tell you through thirst that you need to drink more. Barring any other significant health issues, you'll be fine drinking liquid when your body tells you that you are thirsty. It's as simple as that. There's no need to force down 64 ounces if you're not thirsty. You're body may send you other signals indicating the need for more liquid. Constipation, for example, could be a sign of not enough liquid, although it could also be a sign you need more fiber in your diet.
To conclude, drink when you are thirsty. Do this and you'll most like be fine. :-)