Do We Really Need to Drink Eight Glasses of Water a Day?


The short answer is no. There is absolutely no science behind the health myth that you need to drink eight glasses of water a day. And yet every year we are inundated with article after article and media reports about the dangers of dehydration, as if it is an epidemic that has stricken our nation as a whole.

The truth of the matter is that research has been conducted and effectively de-bunked the eight glasses of water a day myth. Drinking as such made no difference. However, no matter how many research experiments are published, the general public are still not persuaded. This idea has been so fully engrained in society’s popular opinion, that even when proven wrong, people still worry about it.

It is believed that the source of this myth was a 1945 Food and Nutrition Board recommendation that stated people need approximately 2.5 liters of water daily. What they failed to notice though was the sentence that came right after that statement; that most of this quantity is contained in prepared foods. Although water is definitely the best beverage to consume, it’s certainly not your body’s only source of hydration. Worrying about dehydration is also pretty senseless because the human body is finely tuned to signal you to drink long before you are actually dehydrated!

Many studies have tried and failed to prove any substantial link between drinking eight glasses of water daily and improved health benefits. It does not clear skin up, get rid of wrinkles or improve kidney function. Some of these studies have found that children have on average a urine osmolality of 800 mOsm/kg or higher and by drinking more water could bring that down to 8 mOsm/kg less than those who don’t drink enough water. The problem is that 800 mOsm is certainly not defined as being dehydrated.

Overall, people need to start realizing that there is no need for a formal recommendation for a daily amount of water people need. The amount differs significantly based on factors such as what you eat, where you live, how big you are, and what you do.