NHS bosses have set their sights on ‘unhealthy’ sandwiches as part of a clampdown on food and drink that contribute to obesity, diabetes and tooth decay.

Hospital chiefs have been told that three-quarters of pre-packed sandwiches and other savoury pre-packed meals sold in their hospital canteens, stores and vending machines must contain 400 calories or less per serving and must not have more than five grams of saturated fat per 100g.

Hospitals have also been ordered to ensure that 80% of confectionery meets a 250-calorie limit, designed to force the removal of ‘super-size’ chocolate bars and ‘grab bags’ of sugary snacks. In addition, 80% of drinks lines stocked must have less than 5g of added sugar per 100ml.

Failure to meet the targets will mean hospitals lose out on funding ring-fenced for improving the health of staff, patients and their visitors.

“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,” said NHS England chief executive Simon Stevens.

Most sandwiches contain a combination of ingredients that provide a balanced meal, said Jim Winship, director of the British Sandwich & Food to Go Association.

“Hospital nutritionists have said in the past that it is sometimes easier to get a balanced meal into recovering patients via a sandwich than a plated meal, where they don’t eat everything. And, of course, not everyone has the same dietary needs.

“One of the beauties of sandwiches is that they are very flexible and I’m sure that the industry will adapt if this is the new requirement,” he added.

News of the new guidelines comes six months after NHS England announced that retailers including WH Smith, Marks & Spencer, Greggs, Subway, Medirest, ISS and the Royal Voluntary Service had agreed to continue voluntarily reducing sales of sugary drinks to 10% or less of their total drinks sales in hospitals over the coming year.

The Royal Voluntary Service said it had taken an “early lead” on the NHS workforce health agenda by introducing its Healthier Choices programme. In the first quarter of 2017, year-on-year sales of fruit increased 25%, healthier chilled snacks like salad and sushi rose 55% and healthier sweet and savoury snacks like popcorn and dried fruit had more than doubled.

This year Greggs opened a shop in New Cross Hospital, Wolverhampton, focusing on lower-calorie foods, including soup and salads, although sausage rolls, doughnuts and bacon rolls are still available in the outlet. And Cornish business Warrens Bakery has launched a healthy menu delivery app for Plymouth’s Derriford Hospital, delivering soups, smoothies, salads and freshly made sandwiches to hospital staff.

In August, government agency Public Health England announced it was widening its focus from sugar to total calorie intake, a move that puts products including sandwiches, pizza and savoury snacks in its sights.