8 Glasses of Water A Day: Fact Or Fiction?

by Robert Clarke October 09, 2016

There are many general health recommendations that are ingrained in our culture and have been repeated by mothers, through the decades.

While most don't believe that Carrots make us see better in the dark and that eating an Apple a day will, in fact, keep the doctor away; many people are still aiming for their 8 glasses of water a day. But is this classic health recommendation fact or fiction?


Like with most recommendations of this sort, it is hard to locate where it originated from. It is commonly believed that it was from 1945 when the Food and Nutrition Board of the National Research Council wrote the following: 

''A suitable allowance of water for adults is 2.5 liters daily in most instances. An ordinary standard for diverse persons is 1 milliliter for each calorie of food. Most of this quantity is contained in prepared foods.''

It's believed that the above passage was interpreted that one needs to consume 8 glasses of water per day, to maintain optimal hydration and health. Although, the last sentence was apparently ignored: ''Most of this quantity is contained in prepared foods''.

Fact Or Fiction

The truth is, there is no scientific evidence that people who are otherwise healthy, need to consume 8 glasses of water per day. The problem with this myth is that it's associated with water alone, and the people following it only count water towards their daily fluid consumption. This is despite water being in almost everything we consume. It's in fruit, vegetables, juice, and even tea and coffee. 

Now I know most people will scoff at the above and say that coffee doesn't count towards daily water consumption and will actually dehydrate you. This may be another one for the myth basket. Research shows that moderate consumption of coffee has a similar hydrating effect to water. 


The Truth

I know that most people read this and think ''well surely more water is better for you, right?'', but that's not entirely the case either. 

It's commonly believed that the more water you consume, the healthier you are. This was found not to be the case in a study published in 2010, in the British Journal of Nutrition. The study looked at 120,000 individuals, over a 10 year period and tracked the relationship between fluid consumption and mortality from stroke or heart attack. The researchers found no link between less fluid consumption and either form of death. 

If you drink your 8 glasses of water a day, in the hope of having better skin, I also have bad news for you. This study found that consuming 8 glasses of water per day, had no positive effects on skin quality either. 

One other purported benefit of water consumption is weight loss. Aside from having no calories, 8 glasses of water a day will not make you lose weight, but it may possibly help fill you up

So More Water or Not? 

While it is recommended that water is still the healthiest beverage you can consume, it's not the only way you stay hydrated. There is no magic number of cups water you should consume. The age old recommendation of 8 glasses of water per day, is a myth. 

The amount of water you need to consume per day depends on many factors and changes dramatically day in, day out. If you are in a desert or hot environment, sweating, then yes, you will need to consume more water. If you are exercising, you are ill or have other health conditions, you may benefit from and need to consume extra water.

If the above factors aren't relative to you, you probably are consuming enough water and won't benefit from anything extra. There is nothing wrong with consuming a few extra glasses of water a day if you feel like it benefits you. But, keep in mind that it may be psychological. If you are thirsty, by all means, drink. But going out of your way to force down extra water may be overkill and just lead to extra trips to the bathroom, that may not be necessary. Drink more water when you are thirsty and don't waste time stressing about if you are getting 8 glasses or not. 

Robert Clarke
Robert Clarke