New research claims that beer can help people lose weight - when drunk in moderation (honest).

The stunning claim coincides with the opening of the Great British Beer Festival at London's Earls Court.

The Campaign for Real Ale (Camra) said a third of men and women wrongly believe that beer has more calories than other alcoholic drinks.

Swapping wine for beer for just one week would save as many calories as a half-hour jog, Camra claims.

Chief executive Mike Benner said: "It is great news to see the myth of the beer belly finally laid to rest.

"The main message we are putting forward today is that, as a low-alcohol drink, beer can supplement a healthy lifestyle if consumed in a responsible manner."

Brewing expert Professor Charlie Bamforth said: "For years beer has been blighted by a reputation for being more fattening than other alcoholic drinks when in reality the exact opposite is true.

"The major source of calories in any alcoholic drink is the alcohol itself, and because beer is the drinks category with the lowest average alcohol content it is also lowest in calories."

Camra's Great British Beer Festival runs from August 3-7 at Earls Court.

Apart from drink beer, festival goers can play on some traditional pub games, enjoy live music, sample traditional pub snacks and also attend tutored beer tastings.