A Government-commissioned report into nutrition in schools is to recommend that head teachers consider banning packed lunches and stopping pupils leaving at lunchtime to eat at fast-food restaurants.

The report, drawn up for the Department for Education by the founders of the restaurant chain Leon, found that school dinners have improved significantly since celebrity chef Jamie Oliver's high-profile campaign against unhealthy meals such as the Turkey Twizzler.

But the report says take-up of school dinners is low at 43% with children eating packed lunches instead. Only 1% of packed lunches meet the nutritional standards of school food with many containing unhealthy options such as crisps, sweets and chocolate.

Leon co-founder Henry Dimbleby said that head teachers agreed that eating good food not only improved children's health but also their performance in class.

Mr Dimbleby told BBC Radio 4's Today programme that the issue of schools selling chocolate and crisps directly to pupils through vending machines and tuck shops was now "much, much less" of a problem than previously.

But he said: "More than a half of our children bring packed lunches into school and two-thirds of those have crisps in them and two-thirds have confectionery in them. The best schools - the schools that have good food - find ways of making packed lunch the less exciting option. Some of them ban packed lunch altogether."

Encouraging more children to eat in the canteen would have the knock-on effect of making it easier and cheaper to produce nutritious food, he said.

"Canteens are a bit like a restaurant - if you're half empty, you're losing money, said Mr Dimbleby.

"The more children you have in, the better food you can serve at a cheaper price. We did a survey of 400 headteachers. Over 90% believe strongly that food has a direct effect on academic achievement and behaviour."

Mr Dimbleby added: "There's also a growing recognition that food can improve attainment and behaviour, so what we are publishing today is a plan with actions to support headteachers to improve the food in their schools. For example, there's £60 million from Government for expert organisations to work directly with heads to improve the food in their schools. There's money to set up breakfast clubs."

Sharon Hodgson MP, shadow children's minister, said: "Labour vastly improved the quality of school food after Jamie Oliver's important campaign. (Prime minister) David Cameron and (Education Secretary) Michael Gove have deliberately undermined that progress... Parents deserve to have confidence in the quality of school meals. Labour's food standards should apply in all schools, and Michael Gove needs to perform another U-turn to ensure they do."