Super-sized chocolate bars will be banned in hospital shops and canteens as part of the latest drive against obesity, the head of NHS England has announced.

Simon Stevens said there was a need to fight the "super-size snack culture" as he set a 250-calorie limit on sweets and chocolate sold in hospital canteens, shops and vending machines.

This means that most larger packs of chocolate and "grab bags" of sweets will be taken off the shelves in Oxfordshire's four hospitals, with NHS hospitals given a cash boost if they facilitate the move.

Hospital chiefs will need to ensure that 80 per cent of items sold do not exceed the 250-calorie limit.

Mr Stevens said: "The NHS is now stepping up action to combat the super-size snack culture which is causing an epidemic of obesity, preventable diabetes, tooth decay, heart disease and cancer.

"In place of calorie-laden, sugary snacks we want to make healthier food an easy option for hospital staff, patients and visitors."