Two mums have been selling junk food at lunchtime to pupils through railings at a South Yorkshire school.
Rawmarsh Comprehensive stopped letting students leave the school to buy lunch, instead they eat packed lunch or healthy meals from the canteen.
The mums say that kids don't want to eat healthily - and are selling chips, fish and burgers like hot cakes.
But the head says it's important that pupils eat properly at lunch so they can concentrate in afternoon lessons.
From this term, all schools in England are now serving up more healthy school dinners after a campaign led by TV chef Jamie Oliver.
Mum Sam Walker told The Sheffield Star: "This is all down to that Jamie Oliver. Well I don't like him or what he stands for - he is forcing our kids to be more picky about their food."
The school's head teacher John Lambert said he was trying to get the mums' lunch run stopped and added: "Children can have what they want to eat outside school.
"But we are a specialist sports college and the well-being and health of our pupils is what is important to us so we want children to eat what's available in school or bring in a packed lunch."