By Jane Elliott
Health reporter, BBC News
When Billy Murison started back at school this week he had more than a few ideas about what he wanted to eat during his lunch breaks.
Billy Murison's mother worries about what he eats
His mother Janet was left in no doubt about what her seven-year-old does and does not like.
But despite carefully preparing his food and consulting him on what he wants, Billy's sandwich box still sometimes comes home with leftovers.
"When that does happen he certainly gets a grilling about why he asked for something and then did not eat it," said the mother-of-three from London.
"I used to put the occasional treat in his lunch-box, but when he came home the sandwich would probably only have one bite out of it and he had usually left the fruit. So I stopped that."
Because Billy is of a slight build and is underweight, Janet worries about whether he eats enough at school and always cooks a balanced meal at night.
But while she is not there to actually see what he is eating, she believes a packed lunch is the best option.
"He won't eat school dinners and I know at least this way I can monitor what he eats."
Billy agrees. "I like packed lunches because I know what I am going to get that day.
"And I know I will get things I like."
Janet is not alone in worrying about what her children eat at school.
HEALTHY PACKED LUNCHES
At least one portion of fruit and one portion of vegetables every day
Meat, fish or other source of non-dairy protein (eg chickpeas, hummus, or peanut butter) every day
Oily fish, such as salmon, at least once every three weeks
A starchy food such as bread, pasta, rice, couscous, noodles, or potatoes every day
Dairy food such as milk, cheese, yoghurt, fromage frais or custard everyday
Water, fruit juice, semi-skimmed or skimmed milk, yoghurt or milk drinks and smoothies
Source: School Food Trust
The Liberal Democrats announced this week that since healthy meals were introduced in secondary schools 20% fewer children are eating them, claiming that the changes have not been introduced slowly enough for parents, teachers and pupils to get educated about the healthy eating message.
And a recent study shows that packed lunches are far from a perfect option.
Despite 64% of parents consulting their children about what they want in their packed lunch, a study by the Food and Drink Federation shows that more than a third will return with some leftovers.
They add that 28% of children leave their healthy fresh fruit; 26% the staple sandwich and 15% their calcium portion of yoghurt.
But Professor Fergus Lowe, psychologist at Bangor University, Wales, said encouraging healthy eating need not be a struggle.
His team has created a combined reward and education system, which is proving a big success in getting children to eat healthily.
The system, called "Food Dudes", encourages children to eat healthily by using fun DVDs.
Snacks such as crisps. Instead, include nuts, seeds, vegetables and fruit
Confectionery such as chocolate bars, chocolate-coated biscuits and sweets. Cakes and biscuits are allowed but encourage your child to eat these only as part of a balanced meal.
Meat products such as sausage rolls, individual pies, corned meat and sausages should be included only occasionally
Source: School Food Trust
The "Food Dudes" are four super-heroes who gain special powers by eating their favourite fruit and veg. Eating these nutritious foods helps them feed the "Life Force", so they can beat the "Junk Punks" and save the Earth.
First the pupils have a 16-day intensive induction when they are given fruit and vegetables.
They are also read a letter and/or watch a specially designed video of the "Food Dudes".
Each day the children are rewarded with small prizes for successfully eating the fruit and veg and the children keep a diary of fruit and veg they have eaten at home.
Next the children are encouraged to bring their own fruit and veg to school every day in special "Food Dudes" containers.
Classroom wall charts are used to record progress, and children receive "Food Dudes" certificates and further rewards like pens and pencil cases if they make healthy choices.
Professor Lowe said this approach had been shown to work.
"It is not difficult to get children to eat healthily, you just have to encourage them," he said.
"Children are being bombarded with advertising for junk foods and we have to provide a counter culture in schools.
"You have to win the hearts and minds of the children," he said.
His system has already been adopted in the Irish Republic, which uses only packed lunches, as government strategy.
They started with a pilot scheme of 150 primary schools, but it is now being rolled out across the entire country.
Healthy food vital
Anna Denny, a nutritionist with the British Nutrition Foundation, said a good diet is vital for good health and reducing the future risks of heart disease, stroke, cancer, diabetes and osteoporosis.
Food Dudes: the enemies of poor eating
And she said a healthy packed lunch/school dinner plays a vital role in this.
"For school children in particular, a healthy and varied packed lunch is vital in ensuring children get all the nutrients they need to grow healthily and thrive at school.
"School-aged children are growing fast and getting more active, so they need foods that satisfy their energy needs.
The School Food Trust, set up with government cash to promote the education and health of children and young people by improving the quality of food supplied and consumed in schools, advises schools to consult widely with parents and children before introducing any policies on what pupils can eat once inside the school gates.
Help for parents
This week the Trust issued an information pack to help schools and parents provide healthier packed lunches for children.
It includes sample letters to send home to parents from schools so all are aware of school policy.
The trust says sweets, crisps and chocolates should be off the menu, but that cakes and biscuits can still be allowed as treats as long as they do not include sweets or chocolate.
"Each school has a different policy, some allow no treats, others might allow them as a treat, or just on Fridays," said Emma Heesom, who works for the Trust.
"By stating the school policy teachers ensure everyone is aware of the policy and searching a child's lunchbox becomes a last resort."
Dame Anna Hassan, executive head of Millfield's School Clapton, London, whose school won a healthy eating award last year, said her staff had been targeting healthy choices.
She said children had been educated about food and the school menus were published regularly so parents could see what their child is eating.
She added that packed lunches are also under scrutiny.
"All our staff eat their lunches with the children and this enables them to monitor what the children are eating."
She said the school is also preparing to pilot a healthy brunch box, which pupils can buy.
Dave Fann, chair of the primary committee for the National Association of Head Teachers and head of Sherwood Primary School, Fulwood, Preston, said his school also fully endorsed the healthy eating principles, but said it was often difficult to police packed lunches and to ensure everything is eaten.
"At the end of the day these are packed by parents. We don't want to become the lunch box Hitlers."
But he said if they did see children coming in with lunch boxes with crisps and chocolate they would have a quiet word with the parents.
He added that at his school welfare ladies monitor the children who are encouraged to eat their food before going out to play.
Those who leave food are not allowed to put it in the bins, but told to take it home so their parents can see what they are eating.