Scientists say eight glasses of water a day could also be an excessive amount of

Water GlassPA Media

New analysis has discovered that the advisable eight glasses of water a day could also be an excessive amount of.

Scientists from the University of Aberdeen found the advisable consumption of two litres of water a day was typically greater than individuals wanted.

Given round half of the every day consumption of water comes from meals, scientists estimate individuals solely actually need about 1.5 to 1.eight litres per day.

The newest findings had been revealed in Science this week.

Previous analysis into water necessities used surveys utilized to small samples of individuals.

Prof John Speakman from the University of Aberdeen instructed BBC Radio’s Good Morning Scotland: “The original estimate of two litres a day comes from a slight miscalculation.

“The water that we might have to drink is the distinction between the whole water that we have to ingest and the quantity that we get from our meals.

“The way they estimated the amount from food was by asking people how much they eat.

“Because individuals under-report how a lot they eat, there is a misestimate and so that you overestimate the quantity of water that is wanted.”

But scientists have now collaborated across the world to measure exact water turnover using a stable isotope technique.

They surveyed 5,604 people from 23 different countries and aged between eight days and 96 years old.

University Of Aberdeen

University of Aberdeen

Research involved people drinking a glass of water in which some of the hydrogen molecules were replaced by a stable isotope of the element called deuterium.

It is found naturally in the human body and is completely harmless.

The rate of elimination of the extra deuterium shows how quickly water in the body is turning over.

People with a higher water turnover usually need to drink more water.

Research found that this included those living in hot and humid environments and at high altitudes, as well as athletes and pregnant and breastfeeding women.

Energy expenditure is the biggest factor in water turnover. The highest values were observed in men aged 20-35, who turned over an average of 4.2 litres per day.

This decreased with age, averaging 2.5 litres per day for men in their 90s.

Women aged 20-40 averaged a turnover of 3.3 litres, which also declined to 2.5 litres by the age of 90.

Water from meals

But water turnover is not exactly equal to the requirement for drinking water, Prof Speakman said.

He mentioned: “Even if a male in his 20s has a water turnover of 4.2 litres per day, he doesn’t have to drink 4.2 litres of water every day.

“About 15% of this value reflects surface water exchange and water produced from metabolism.

“The precise required water consumption is about 3.6 litres per day. Since most meals additionally comprise water, a considerable quantity of water is supplied simply by consuming.

“This study shows that the common suggestion that we should all be drinking eight glasses of water is probably too high for most people in most situations and a ‘one-size-fits-all policy’ for water intake is not supported by this data.”

He mentioned the analysis represented a giant step forwards in predicting future water wants.

But there may be negatives in consuming an excessive amount of water.

“Clean drinking water isn’t free,” Prof Speakman mentioned.

“If people on average drink half a litre more than they need and you multiply that by 40 million adults in the UK, that means that we’re needlessly drinking and peeing 20 million litres of water that we have to supply.

“There is a value in doing that.”