The Government's Jamie Oliver inspired drive to create healthier school meals is reportedly being jeopardised by students operating a black-market trade in banned food including burgers and chocolate.
Newly installed healthy menus in school canteens and the removal of junk food from vending machines have created a gap in the market that students have been quick to fill, according to The Times.
The headteacher of a Dorset secondary school told the newspaper how he had broken up a "seriously big smuggling operation" run by a schoolboy.
A number of other headteachers confirmed that similar schemes were taking place up and down the country.
"It has happened to us," said one. "Kids with motorbikes buying McDonald's burgers in bulk and flogging them in the playground.
"We are a business and enterprise school in Essex so I guess I should not be surprised. When challenged, the boy at the centre said he was just being enterprising."
Brian Lightman, president of the Association of School and College Leaders, said that the healthy eating initiative would only succeed if students were allowed a say.
"Because these changes have been imposed without allowing time for them to gain a sense of ownership, schools are reporting cases of students finding innovative ways around the new regulations," he said.
Also see Caterer and Hotelkeeper's round-table debate on primary school dinners on 8 May for more on the school meals debate.
By Daniel Thomas