Humans do not need to drink eight glasses of water a day.
Eight glasses of water a day is unnecessary
The recommendation to drink the amount has become accepted wisdom and usually appears in health guidance but a new scientific study suggests that the figure is excessive for many people.
Yosuke Yamada, of the National Institute of Biomedical Innovation, Health and Nutrition in Japan, said: "The current recommendation is not supported scientifically at all.
"Most of the scientists are not sure where this recommendation came from."
Yamada explained that previous estimates have not taken into account the water content of food, which contributes a substantial proportion of a person's intake.
He said: "If you eat just 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 per cent of your water needs from food."