DRINKING just one glass of water a day in place of beer or fizzy drinks slashes the risk of obesity by up to a fifth, researchers have found.
Those who replace unhealthy drinks with water once a day for four years also lose weight, according to a study of nearly 16,000 people.
The findings, presented at the European Congress on Obesity in Portugal, showed giving up one 330ml bottle of beer a day and drinking water instead cut the risk of obesity by 20 per cent.
And if you gave up a 200ml glass of fizzy drink, swapping it for water, you will cut your risk of becoming obese by 15 per cent.
The researchers from the University of Navarra in Spain said the figures held true even when factors such as exercise levels, family history of obesity and snacking between meals were taken into account.
But they found the same results were not found for 15 other drinks, including wine, fruit juice, coffee and milk.
Experts suggested the fact beer and fizzy drinks are so calorific may be to blame.
A bottle of beer typically contains 142 calories, while a 200ml glass of soft drink such as Coca-Cola typically contains 78 calories.
Those who drink beer are also more likely to consume extra calories, such as on a night out, while people who drink sugary drinks probably also have unhealthy diets, they said.
Paul Christiansen, a researcher in addiction and obesity from the University of Liverpool, said: It's a fairly logical step. You are taking empty calories out of the diet.
Alcohol within itself is incredibly calorific, second only to fat, and beer is an easy way to consume alcohol.
Take away empty calories and switch to water of course you will see a benefit.' Tam Fry, of the National Obesity Forum, said: In the end, if you're thirsty, water is by far the best drink in town.'
© Daily Mail