Hospitals will be offered cash incentives to help improve the health of their staff, the head of the NHS in England has said.
Simon Stevens said the NHS should "practice what it preaches" by tackling obesity and improving the well-being of its 1.3 million staff.
Health services can claim a share of a £600 million pot from next month if they limit the availability of junk food and provide physiotherapy and mental health support.
The measures are intended to help cut the annual £2.4 billion NHS sickness bill for staff, with mental health and musculoskeletal problems being the two biggest causes.
Mr Stevens, chief executive of NHS England, said: "As the largest employer in Europe, the NHS needs to practice what it preaches by offering better support for the health and well-being of our own 1.3 million staff.
"A good place to start is by tackling the sources of staff sickness absence including mental health and musculoskeletal injuries, while doing our bit to end the nation's obesity epidemic by ditching junk food and sugary drinks in place of tasty, healthy and affordable alternatives.
"If we can do this well, we hope that more parts of the public and private sector will see the sense of it and also take the plunge."
To qualify for incentives, hospitals will have to remove price promotions and checkout displays on sugary drinks and high-fat or salty foods and increase the number of front-line staff given the winter flu jab.
Trust bosses will also be compelled to reveal how many fast foot outlets are on their premises in preparation for the NHS "sugar tax", which will see hospitals start charging more for high-sugar drinks and snacks in their cafes and vending machines to deter patients, visitors and staff from buying them.
Medics' unions and campaigners welcomed the announcement but called on the NHS to do more.
Janet Davies, chief executive of the Royal College of Nursing, said the investment was "positive" and could lead to improved care for patients.
She added: "Too often in the past, the NHS has failed to take care of its staff in the same excellent way it takes care of patients.
"This initiative must be accompanied by improved access to flexible working and a concerted effort to reduce the stress experienced when staff cannot properly care for patients because of insufficient staffing levels."
Professor Sheila Hollins, British Medical Association board of science chairwoman, said: "With the NHS best-placed to set a good example and encourage patients and the public to eat healthier diets, we hope this is simply the first step which will lead to the end of the sale of all unhealthy food and drink hospitals in all NHS hospitals across the UK."
But Tam Fry, spokesman for the National Obesity Forum, said: "Nowhere in the announcement does the NHS acknowledge that some 700,000 of its staff are overweight or obese or state how it proposes to evaluate if its £600 million financial incentive is value for money.
"All this help can be laid on but proof is needed that employees' health and fitness will improve. A taste of their own medicine is required."