By Sean Coughlan
BBC News education reporter
Healthy meals should be made free for all pupils, says the school caterers' professional body.
Schools have come under pressure to raise the standard of meals
This would be the real solution to improving children's diets, said Neil Porter, chairman of the Local Authority Caterers Association.
The long-term health benefits would soon outweigh the extra shorter-term costs, he said.
"You could really ensure that nutritional standards are met," Mr Porter told the BBC News website.
He said that if people were serious about wanting better school food, they had to accept it could not be on the basis of always driving down costs.
"The big problem we have is that it's been commercially driven. And the big question is 'Should school catering be treated as a business?' And quite frankly, I don't think it should be," said Mr Porter, whose association represents caterers in the private and public sectors.
"The way forward is for meals without charge for all pupils."
WINNING SCHOOL MENU
Aberdeen Angus tortilla with Peter Pan salad (beef wrapped in a tortilla with rice and a crunchy salad)
Glamis Castle Cups with Glen Clova Cream (chocolate-drizzled brandy basket filled with raspberry and rhubarb dessert)
Prepared for 80p in 90 minutes by Lynne Howe (above) of Tannadice Primary School, Forfar
Since celebrity chef Jamie Oliver highlighted the dismal food on offer in some schools in south London, there has been a barrage of proposals to raise standards.
This included the government promising £280m to make meals healthier - followed swiftly by allegations that they were jumping on a parent-friendly bandwagon.
Speaking in Coventry, ahead of the School Chef of the Year Award, Mr Porter said if parents and politicians really wanted better school meals they needed to consider more root-and-branch approaches.
The most direct route to this would be to give all pupils a healthy meal without charging parents - as already happens in countries such as the educational top performer, Finland.
It would be a no-nonsense way of tackling the problem, Mr Porter said, cutting through arguments about how much parents could afford and about how to regulate providers and sub-contractors.
"If you can ensure that children throughout their school life are in a culture of eating healthily, they're going to carry that into the rest of their lives. This means major long-term benefits for the health service. "
'Crisps on way to school'
From the school's perspective, it would cut down on the bureaucracy of cash collection.
For pupils, it would take away the choice of whether to spend the money on crisps on the way to school.
"If you did the calculation on these savings, it would soon reduce the cost."
Jamie Oliver was disappointed by existing school food
In terms of how much it would cost, the only authority to currently provide free school meals (for all primary children) is Hull - at a cost of £3.8m per year.
If this was taken as a local authority average, it would mean about £600m across England.
But Mr Porter said that it seems unlikely that the political will existed for such a direct intervention.
There were fears about appearing to be a "nanny state".
He also said it would mean reversing compulsory competitive tendering for school meal contracts, where some local authorities "evaluate on price and price alone and don't take into account the true quality of the service".
There had to be more "joined-up thinking" over improving food standards and investment in staff training, modern kitchen facilities and dining areas big enough for the numbers of pupils.
Although optimistic the "tide is turning" on school meals, he warned there were practical limitations on the improvements promised from extra government funding. For example, some schools had no kitchen to improve.
"If I'm honest, I don't believe that any of this funding will impact on that. Transported food is a really old-fashioned way of providing meals.
"No matter what energy and hard work you put into producing those meals, once they go into a box to be transported, you can't control how it's treated. It can be soul destroying."
But he was unconvinced by stories about schools unable to escape lengthy contracts with meal providers or of private finance contracts stopping schools having their own kitchens.
"It's up to the local authority. They can specify whether there is going to be a kitchen in a new school. The provider is only working to what's in the contract."
The school chefs award ceremony, held in Henley College, heard that much creativity existed in school kitchens, but had been missed in the hue and cry prompted by Jamie Oliver's television series.
The winner of the competition, Lynne Howe, who cooks at Tannadice primary school, in Forfar, Angus, said school meals were much better than had been depicted.
Her own winning meal had been created at a cost of 80p - and she said that similar efforts could be produced by other schools.
"I just hope that all the promises about school meals won't disappear again after 5 May," she said.