“This study shows that the common suggestion that we should all be drinking eight glasses of water – or around two litres a day - 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,” said Prof John Speakman of the University of Aberdeen, a co-author.

“I think it’s a recommendation that many people just ignore and follow what their body is telling them,” he said.