By Sean Coughlan
BBC News Online education staff
Teachers have called for a clampdown on "pernicious" junk food advertising aimed at children.
Later this year, two million infants will receive free fruit each day
The National Union of Teachers says poor diet is causing obesity and ill-health among youngsters - and it wants tighter controls on food advertising.
The call follows a government decision to revise nutritional standards for school meals in England.
This is part of a "healthy living blueprint" which promotes an improved diet and more physical exercise.
The "joined up" plan to promote children's health, backed by both the Department for Education and Skills and the Department of Health, was launched on Monday at Shacklewell primary school in Hackney, east London.
Fizzy drink ban?
The school's head teacher, Darra McFadyean, also voiced support for restrictions on the type of food advertising aimed at youngsters.
In her school, which places a strong emphasis on children's health, fizzy drinks are banned. But she says efforts to raise children's awareness of a healthy diet are running against the tide of marketing.
"I would love somebody to do something about the way they advertise on children's television. It's overpowering."
NUT leader, Steve Sinnott, had called on the government "to understand the overwhelming influence of rampant commercialisation".
"Obesity and poor nutrition affects learning," he said.
Health Secretary John Reid, who attended the launch, left the door open for a more interventionist approach to children's diet in schools.
Although saying he would not comment on any specific calls for tougher food guidelines, such as stopping the sale of fizzy drinks in schools, Dr Reid said there was a responsibility to act on behalf of children.
"Children are not always in a position to make the same mature choices as adults. So there is a greater responsibility on behalf of society to intervene, assist, encourage and prohibit, when it comes to schools," said Dr Reid.
Food for thought
Shacklewell primary school, which serves a deprived inner-city area, has seen a sharp improvement in test results in recent years - and the head says that a better diet, more exercise and approaches such as teaching "emotional literacy" have underpinned pupils' progress.
Brown bread on the menu at Shacklewell school in Hackney
The school has its own fruit and vegetable garden, healthy eating is promoted at breakfast and lunchtime and children have physical exercise every day.
But while such projects provide examples of how children can be encouraged to make healthier choices, the overall national picture shows more of an uphill struggle, with surveys raising concerns about rising levels of childhood obesity.
Dr Reid said changing lifestyles were resulting in young people taking less exercise - and had contributed to a tripling in levels of obesity in the past three decades.
He said there was a "staggering" reduction in the number of miles walked by children each week, compared to previous generations who walked to school and who played more sport or ran around after school, rather than watched television or played computer games.
But he was optimistic that there could be positive changes in behaviour. And as an example, he said giving a piece of fruit to infants each day had encouraged children to eat more fruit at home.
"It was having an effect, parents told us. That's why we're extending it to all schools," said Dr Reid.
This scheme, initially piloted in inner-city areas, will be extended this autumn so that two million infants receive a free piece of fruit each day at school.
Dr Reid said that children needed to be taught in "interesting ways about the benefits of healthy living".
The east London school has a breakfast club for children
"It's about offering them options other than the traditional chicken and chips, incorporating play and sport within their daily life."
The healthy-living efforts at Shacklewell school have emphasised the need for a holistic approach to improving children's lifestyles.
And Nicola Baboneau of the Learning Trust (which runs schools in Hackney), says there are clear links between physical well-being, emotional well-being and pupils' behaviour and academic achievement.
She says the challenge is to help show children and their families that that they can make decisions about their own health - and that they can resist outside pressures to opt for the junk-food lifestyle.
It's not only about money - as she says there is plenty of cheap fresh food available from local markets.
But this is not the first time the Westminster government will have launched a healthy schools initiative - with promises of a new, healthier future for school meals.
And Education Secretary Charles Clarke said there were still variations in the quality of school meals.
"I accept that the situation isn't as it should be but I don't think it is any disgrace to say that if they are not up to the mark that we should change them," he said.