Do You Actually Need to Drink 8 Glasses of Water Each Day?


Everyone’s heard the old axiom that we’re supposed to drink eight glasses of water a day. Otherwise, we risk being “chronically dehydrated,” right?

drinking water

But do we really need to drink that many glasses of water?

The short answer is no, not really, but there’s a little more to it than a simple yes or no. Your water intake needs vary based on several factors, including health conditions, where you live, and how active you are.

So, what’s the deal with the recommended eight glasses?

How This Idea Originated

Way back in 1945, the National Academy of Sciences Food and Nutrition Board released a publication stating that “a suitable allowance of water for adults is 2.5 liters daily in most instances.” This equates to about eight glasses.

There’s just one thing that a lot of people tend to leave out, however. The original recommendation also mentioned that “most of this quantity is contained in prepared foods.”

In other words, most healthy adults may not need to go all crazy on the water consumption. And this is especially true if lots of fruits and veggies are consumed. Plus, as many nutritionists at the time also noted, many other beverages also count to some degree as well. Even other sources to which the idea has been attributed mentioned the same.

What Science Says

There’s actually no scientific evidence to suggest you need to drink eight glasses of water a day. However, not drinking enough – based on your own individual circumstances – can lead to mild dehydration. When that occurs, you might experience headaches, fatigue, and/or an impaired mood.

The good news is that human beings have a built-in indicator to help stave off dehydration – it’s called thirst. The key is to always drink something when you’re thirsty.

And yes, it’s ok to quench that thirst with beverages other than water. Though alcoholic, caffeinated, and heavily-sweetened ones should only be consumed in moderation.

Reese Allen
Reese Allen knows firsthand how important it is to take care of your health. A severe car accident in college left Reese with more than a year of physical therapy as he relearned to walk. Now, Reese runs at least one 10K a month and is training for his first marathon. Never miss an update from Healthy Tip Daily—be sure to allow notifications and get the latest tips on living your best, healthiest life.