Education Secretary Charles Clarke has announced a shake-up of the traditional school lunch menu as part of a bid to tackle obesity among children.
Headteachers will be asked to develop a school-wide food policy setting out how they will provide more nutritious food in their tuck shops, vending machines and cooking classes.
And schools will be asked to increase the amount of physical activity in the timetable.
The plans are part of a £5.7 million "Healthy Living Blueprint" launched today by Mr Clarke and Health Secretary John Reid. It sees the Department for Education and the Department of Health joining forces to encourage pupils to lead healthier lives.
The blueprint says that schools have a key role to play in encouraging children to eat healthier food, and should try to steer them away from foods heavy in salt, sugar and saturated fat.
"A challenge for schools is to balance the benefits of food promotional activity including sponsorship, advertising and branding of materials, with the ethos of the healthy school and the whole school approach to healthy eating," it says.
Schools will be asked to promote the '5 -a- Day' message, encouraging all children to eat at least five portions of fruit and vegetables a day. By the end of 2004, the blueprint says, all 4-6 year olds in LEA-maintained infant, primary and special schools will be eligible for a free piece of fruit or vegetable every school day.
To support teachers, the Government will invest over £1 million in school meals. It will revise nutritional standards for secondary schools, give additional support to heads and governors in providing a healthy school meals' service, and improve training for catering staff in schools.
In the section on exercise, the blueprint re-affirms the Government's commitment to give every pupil at least two hours of sport a week. It also calls on schools to do more to educate pupils about healthy lifestyles through tackling issues such as drugs, sex, alcohol and smoking.
Launching the document, Mr Clarke said he wanted primary schools to stay open for longer - up to ten hours a day - to give children of busy parents the chance to exercise and eat healthy food.
He said: "Good health and effective learning go hand in hand. A healthy body leads to a healthy mind. The partnership of parents and school is critical in shaping good health in children and schools are well-placed to lead by example."
The latest initiative comes after the Government introduced minimum nutritional standards for school dinners in 2001.
It introduced a £77 million programme delivering two million pupils a free piece of fruit or vegetable every day.
However, Paul Burstow, the Liberal Democrats health spokesman, said the latest initiative was too little, too late.
"Ministers sanctioned rules that let cheap, low quality, high fat, high salt and high sugar foods on to the menus," he said.
"Now they are belatedly taking action. Getting the standards for school meals right is an essential foundation in building a culture of healthy schools which can help begin to turn the tide of childhood obesity in this country.
"We need more than an announcement on what will happen in the future. We need a clear timetable of when the changes will happen and a sense of urgency to make it happen."