Do you really need eight glasses of water a day? New study shows maybe not

It is common knowledge that the ideal quantity of water the average person should drink in a day is eight glasses. But now, a new study has found that this requirement may be too excessive for most people. Instead, the research suggests that many people may actually require between 1.5 and 1.8 litres.

How much is too much?

A study described as the most rigorous one to date on water turnover found that the amount of water that people need to consume varies widely. One of the co-authors, Dale Schoeller who’s also studied water and metabolism for decades explained:

The science has never supported the old eight glasses thing as an appropriate guideline, if only because it confused total water turnover with water from beverages and a lot of your water comes from the food you eat.

The study was published in the journal Science, assessed the water intake of 5,604 people aged between eight days and 96 years old from 23 countries.

Water in food

According to the study, water needs peak for men in their 20s, while they remain level for women from the age of 20 to 55 — but only vary by about two glasses for each gender, with men requiring more. An issue that the researchers found with the previous 8 x 8 rule was that it did not take into account the water content of food, which can contribute a substantial proportion of our overall intake. Yosuke Yamada is one of the lead authors:

If you just eat bread and bacon and eggs you will not get much water from food, but if you eat meat, vegetables, fish, pasta and rice you can get about 50% of your water needs from food.

So how much water should you drink in a day? That, the study did not make the recommendation.

Sources used:

Women’s Health Australia: Turns Out You Might Not Need To Drink 8 Glasses Of Water A Day, According To Study

The Guardian: Eight glasses of water a day excessive for most people, study suggests

New York Post: The rule you need eight glasses of water a day is nonsense: study