The important thing is to make sure kids are offered a good choice of good food in schools Jamie Oliver

But he warned that it would not work everywhere, and said the priority was to offer children good food in school.

Some of the area's schools have already begun the policy to discourage children from going out to buy takeaways.

The TV chef, who led a campaign for better school meals, said it would be interesting to see how it will work.

Denbighshire Council wants to reverse a slump in school meal take-up and is considering rolling out the idea across the county.

Latest figures from Denbighshire Council show that fewer than half of primary school pupils eat school meals, compared with 55% in 2004 - 2005.

Within secondary schools in the same period, numbers also fell by more than 50,000 to 573,000.

'Good choice'

A working group has drawn up draft guidance for head teachers to establish an all-school policy "encouraging schools to retain pupils on school sites over the lunch break."

School governors, head teachers and teaching unions will now be asked for their views on the draft, according to a report to be discussed by councillors.

Mr Oliver, who pushed for schools to be allocated more money to provide healthier meals, said: "It will be interesting to see how Denbighshire gets on with this idea.

"Keeping children on school premises at lunchtimes is one possible solution, but it wouldn't work for every council or for every school.

"The important thing is to make sure kids are offered a good choice of good food in schools."

Probably fish and chips does still have the edge but if that option is withdrawn, or at least limited, students do quite quickly get used to... and enjoy, the new healthy eating menus Steve Price, Denbighshire Council

Despite recent claims by politicians that the school meals service is in meltdown, many schools were making real progress in persuading children to accept healthier menus, he said.

He added: "It's important that the food is tasty, that the dinner ladies are being supported, that the dining room is good and not too crowded and that the kids have enough time to get their food and eat it during their break."

Many children want hand-held food so they can "eat it and go," he said, which is why taking food like nutritious burgers and wraps into the playground on his TV series had worked.

Steve Price, of Denbighshire Council, said the policy of banning from leaving in the lunch hour was already in place at some schools and had "worked quite successfully".

Mr Oliver said this week that support for healthy meals must continue

He said: "Requiring pupils without authorisation from the parents or guardians to leave the site to stay on site that does happen but it doesn't happen throughout the county and that's what the policy really is looking at.

"To roll out the good practises and to assist governing bodies, the heads and the school staff to do that."

More than 4,000 questionnaires had been given out to pupils as part of extensive market research done by the council.

This had been used to develop new menus going out this week to parents, he said.

Feedback showed pupils were not against the healthy eating initiative, he said, adding: "We've found that probably fish and chips does still have the edge but if that option is withdrawn, or at least limited, students do quite quickly get used to... and enjoy, the new healthy eating menus."

The new menus would feature the likes of chips and homemade pizza one day a week with options like roast dinner, filled rolls or baked fresh food on other days.