Junk food could be off the menu in hospital canteens as o verweight doctors and nurses are encouraged to slim down to set a good example to patients.

Burgers and chips will be swapped for healthier options and staff will be able to take part in weight-loss competitions under plans being considered by NHS England chief executive Simon Stevens, The Sun reported.

Around 700,000 of the NHS's 1.3 million staff are either overweight or obese, the newspaper claims, and Mr Stevens wants to introduce incentives for them to lose weight.

More gyms are to be built and NHS sites will become increasingly cycle friendly, while prizes such as pedometers will be on offer for staff who shed the pounds.

Mr Stevens said the rising obesity epidemic of recent years was bad both for people's health and for the health service itself, and t ackling obesity would put less pressure on the nation's finances and would free up funding for new treatments.

Recent figures show that almost three quarters of people aged 45 to 74 in England are either overweight or obese.

Young adults are the only age group who have a normal average body mass index, according to the Health and Social Care Information Centre.

The NHS is facing a funding crisis and senior health figures have said it may need an extra £30 billion by 2020 to maintain the current level of service provision.

Promising to tackle the obesity problem, Mr Stevens told The Sun: "It's hard for the NHS to talk about how important this is if we don't get our own act together. I think the NHS has got to take an example in helping our own staff and hopefully other employers will follow suit.

"A lot of the food in hospital canteens, not just for patients, but for staff, is chips and burgers. The NHS as an employer, for our own nurses and other staff, could we offer positive incentives? Yes, I think we could. And some hospitals have begun doing that."

Mr Stevens also called on parents to help keep their children healthy by swapping juices and fizzy drinks during meal times for water or milk.

Looking to the future, he said that further progress in technology would keep patients out of hospital as people live longer, and he wants greater partnership between the NHS and social services.

He said: "What's great about the NHS can't excuse what needs to change about the NHS. That is the approach that we have got to take. We've got to support people doing great things, nurses, doctors, the frontline of healthcare. But we've also got to raise our game."

He also called for thousands more GPs to be trained, and wants to give them more power to make decisions about how NHS money is spent.