Do you really need to drink eight glasses of water a day?

Article Date: 5th November 2015

Many of us have been told at some point that we must drink eight glasses of water each day. By imbibing this amount of H₂O we will feel healthier and look younger – so the advice goes.

However, there is one drawback to this theory – it just doesn’t hold, well, water.

One health researcher has become so annoyed with people passing this guidance off as fact that he recently published a rebuke in the New York Times to put the record straight.

“If there is one health myth that will not die, it is this: You should drink eight glasses of water a day. It’s just not true. There is no science behind it,” wrote Aaron Carroll, a professor of paediatrics at Indiana University School of Medicine.

It is generally accepted that the eight glasses of water a day myth originates from a paper published in 1945 by the Food and Nutrition Board of the National Research Council in the U.S., which recommended that a “suitable allowance of water for adults” is 2.5 litres per day. However, what has been lost over time is that the advice goes on to say that most of this water can be found in “prepared foods”.

More recent studies have shown that there are no real health benefits from drinking eight glasses of water each day.

So how much should you drink?

This very much depends on your size, your personal needs and how active you are.

The best advice is to listen to your body. Rather than religiously keep track of every glass of water you take on board, drink when you are thirsty and have a drink with your meal. Much of the water we need will come from other drinks we enjoy, such as tea, coffee and fruit juice – although we would advise not drinking too many sugary drinks or overdoing it on the caffeine.

A lot of your water intake will come from the food you eat. But just what constitutes a healthy diet is a whole different subject area best saved for another blog.