We all know that we should make sure to be drinking plenty of water throughout the day. The general rule of thumb is to drink eight glasses of water per day. But where does that figure come from? Is it based on any science, or just a rounded figure? Is that really how much you need – and does it apply to everyone?
The benefits of getting enough hydration are well-known. Our bodies are dominantly made up of water, so it is crucial to be replenished so that all of our bodily processes are running at their best. It can aid in digestion, improve the health of your skin, up your odds of losing weight, and even ward off deadly diseases such as cancer.
But how much should you be drinking really?
What’s the Right Amount of Water Per Day?
A couple of hundred years ago, water was only something that was consumed when someone was close to death. According to this article on BBC.com which quotes Vincent Preissnitz, the founder of hydropathy (the “water cure”), only those who were “reduced to the last stage of poverty satisfy their thirst with water.” Times sure have changed since then, as the sales of bottled water outpace those of soda. That’s a healthy change that I certainly welcome.
As mentioned above, the general rule for how much you should drink is called the “8×8 rule”, meaning the consumption of 8 glasses of 8 ounces of water per day. This comes out to just shy of two liters daily. However, according to the BBC article linked above, there is no scientific backing to that rule, nor is there any guideline by officials that says we should be drinking that much.
It seems that this rule comes after misinterpretation of a couple of guidelines that were set forth decades ago. The first is advisement by the US Food and Nutrition Board of the National Research Council in 1945, which called for one millimeter of water per calorie of food consumed. The second was in 1974 from a book called Nutrition for Good Health, which recommended six to eight glasses of water per day. In both these cases, water ingested through food and other beverage sources also counts to the daily total.
So How Much Do You Really Need?
We have always been told that if we are feeling thirsty, that means we are already severely dehydrated. The fact of the matter, according to experts, is that we do not need any more water than what our bodies tell us to have by signaling a feeling of thirst.
As told by Courtney Kipps, consultant sports physician and principal clinical teaching fellow of Sports Medicine, Exercise and Health and UCL, and medical director of Blenheim and London Triathlons quoted by the BBC:
“If you listen to your body, it’ll tell you when thirsty. The myth that it’s too late when you’re thirsty is based on the supposition that thirst is an imperfect marker of a fluid deficit, but why should everything else in the body be perfect and thirst be imperfect? It’s worked very well for thousands of years of human evolution.”
So there you have it! While eight glasses per day is probably a good number to shoot for, don’t take it as gospel that you must have that amount. If you’re thirsty, have a drink. Don’t stress yourself out too much to hit a magic number. When your body needs hydration, it will let you know.