Researchers say the recommended intake of 2 litres a day rarely matches our needs.
The old adage of eight glasses a day is being challenged.
Researchers at the University of Aberdeen say the recommended intake of 2-litres a day rarely matches our needs.
Around half of our daily water intake comes from food, and scientists estimate we only really need around 1.5 to 1.8 litres a day.
However, people who live in hot climates or high altitudes, athletes, and breastfeeding women need to drink more fluids, as their 'water turnover' rate is higher.