The Government is to order a review of school meals in an attempt to stop pupils eating too many chips and fatty foods at lunchtime.
Charles Clarke, the Secretary of State for Education, will announce the review tomorrow as the focal point of a campaign to reduce obesity among schoolchildren by the end of the decade.
In 2001, ministers introduced minimum nutritional standards for school dinners for the first time for 20 years. Tomorrow's announcement is an admission that the guidelines have failed to deliver and need to be strengthened.
"The guidelines encouraged schools to offer pupils a choice between, say, chicken nuggets and chips, and pasta and salad," said a spokesman for the Department for Education and Skills. "What they have proved is that you can take a horse to water but you can't make it drink."
The review will look at ways in which ministers can order a reduction in the levels of salt, sugar and saturated fats in school dinners. "We want to reduce chip intake not to ban it," said the spokesman.
The initiative comes just a few days after one of the country's largest retail firms revealed the size of school uniforms had grown over the past few decades.
John Lewis said it was now regularly selling girls' blouses with a 44in chest, whereas 50 years ago the maximum size was 36in. Skirt waist sizes have gone up from 28in to 34in. In addition, the maximum boys' collar size has increased from 14in to 17in.
The Government is also to issue guidance on how schools should be encouraging their pupils to adopt a more healthy lifestyle. The blueprint will encourage them to adopt a "whole-school" approach to healthy living - increasing the amount of physical activity pupils take part in.
Ministers are aiming to guarantee every pupil at least two hours of PE a week. The latest figures show that only 62 per cent of schoolchildren receive this amount.
Other measures being advocated include lessons in how to achieve a balanced diet as part of food technology courses. Sports co-ordinators will be drafted into schools to increase the amount of competitive games played. And help will be given to schools to build bicycle sheds to encourage more youngsters to cycle to school.
"Good health and effective learning go hand in hand," Mr Clarke said last night. "A healthy body leads to a healthy mind."