Food retailers in hospitals across England have been rated according to whether they are meeting healthy eating targets set by NHS England, with Subway and Burger King at the bottom of the rankings.
Household names like Costa, Starbucks and Subway have been rated by the Campaign for Better Hospital Food for their committment to improving the amount of healthy food offered to patients, staff and visitors.
The Royal Voluntary Service tops the table, while Subway and Burger King - which has an outlet at Addenbrooke's Hospital in Cambridge - are at the bottom.
NHS England has set targets for healthier food by March, along with targets on price promotions and food advertising.
Katherine Button, from the Campaign for Better Hospital Food, said: "It's disappointing that Subway and Burger King alone out of all the major brands serving food in hospitals are the only two we found not to be working towards NHS England targets on promotion of healthier food.
"The healthier option should be the easier option in hospitals, and at the moment Subway and Burger King appear to be holding back moves towards a healthier NHS."
According to the research, Subway - which has 12 outlets in hospitals - has failed to meet three out of the four targets for promoting healthy food.
A statement from Subway said it was "disappointed that the survey does not recognise the commitment that the Subway brand has made in offering our customers a healthier on-the-go choice".
"The Subway brand is a proud partner of Heart Research UK which supports a customer's choice of a low fat sub, as demonstrated by the red healthy heart logo on our menu boards in all stores, including those in hospitals."