By Mike Baker
BBC News education correspondent
There is a tendency in politics, and in the media too, to focus on a big announcement and then to move on without following it through.
There is a real danger that this could happen with school dinners.
After the powerful television campaign by the chef Jamie Oliver, the poor nutritional quality of school meals became an election issue in the spring.
In the heat of the election campaign, the government announced £220m over three years and set up a School Meals Review Panel to make recommendations for new nutritional standards.
Two weeks ago, at the Labour Party conference, we had the fanfare: the banning of "junk food" from school canteens and vending machines.
Cheap burgers and processed bangers will no longer be served and children will not be able to buy fizzy drinks and chocolate bars.
So far, so good - yet no one should think that is the end of the matter. This week a national conference on healthy eating in schools highlighted just how much remains to be done and how precarious are the gains so far.
Two major problems were highlighted: a lack of money to implement change and a need to educate pupils, parents, and school kitchen staff.
Food and behaviour
There was also a positive note. Research evidence suggests that if we really can crack the problem of poor nutrition amongst children, we may simultaneously solve many of the problems of anti-social behaviour, exclusions and poor literacy standards that beset schools.
That might seem a big claim but it came from an authoritative, and scientific, source.
Bernard Gesch, a senior research scientist in the Department of Physiology at Oxford University, riveted the conference with his presentation linking food to behaviour.
His evidence is based on research he carried out, not in schools, but in prisons.
This involved giving one group of prisoners food supplements containing vitamins, minerals and essential fatty acids. Another group were given placebos. Neither prisoners nor staff knew who was on the supplements and who was receiving the placebo.
The supplements did no more than ensure that the prisoners taking them would meet the government standard for prison diets (as in schools, while nutritious food was available, the inmates did not always choose it).
School meal nutritional standards will come in 2008 and 2009
The results were quite stark: the anti-social behaviours of those on the food supplements fell by over 35%. The most serious violent acts fell by even more. There was no change for those on the placebo.
Another experiment, conducted by Dr Alex Richardson of Oxford University, involved young children, aged from six to 11, in Durham.
All these children had specific difficulties in motor coordination, over 30% had Attention Deficit Hyperactivity Disorders (ADHD), and 40% had specific learning difficulties and were more than two years behind in reading and spelling.
The experiment provided the children with supplements containing Omega-3 and Omega-6 fatty acids and vitamin E.
Again, the results were very clear. Compared with the expected progress for normal children, the recipients of the supplements improved their reading ability at more than three times the normal rate, and more than twice the rate in spelling, over three months of treatment.
There were also significant improvements in their ADHD symptoms.
Mr Gesch also referred to research in schools in the US, where a new regime of banning vending machines, providing nutritional education, better food and low dose vitamin-mineral tablets had improved both behaviour and academic standards.
In this experiment with five to 10 year olds, after one year, exclusions had fallen by 80%, violent acts were down by 97%, and the school's test scores in maths and English had shot up, taking it from being the lowest in the school district to first and second in maths and English respectively.
So, compared with the hundreds of millions being spent on reducing exclusions and truancy, and raising standards, the government might do better to channel more funds into school children's diets.
Which brings us back to the problem of money. The chair of the School Meals Review Panel, Suzi Leather, told the conference that the cost of implementing nutrition standards in schools in England would be £168m a year.
Her estimate would amount to around £500m over three years. So far, the government has given only £220m for that period.
The Education Secretary, Ruth Kelly, had acknowledged the need for more. Will it be forthcoming, especially as the school meals issue falls out of the headlines?
On top of that, Ms Leather says an additional £289m is needed, as a one-off, to refurbish school kitchens and dining rooms.
While the ban on junk food, which has legal backing from 2006, got plenty of media attention, less notice was given to the timetable for introducing nutrition standards.
The School Meals Review Panel, recognising the obstacles to be overcome, set this at 2008 for primary schools and 2009 for secondary schools.
While that may have been realistic, it means that many school dinners may continue to lack the nutritional content required for healthy living.
This is serious, as we have not yet seen the full impact of poor diet on children's health. As Ms Leather pointed out, the health problems of today's young children will start to show in the teenagers and young adults of the future.
By 2020 it is estimated that one in five boys, and one in three girls, will be obese. That is not just overweight, but clinically obese.
In view of the evidence of the link between nutrition and behaviour and literacy levels, surely it is time for government to fund some bigger studies to see what can be achieved by a programme of vitamin supplements for pupils, particularly during these next few years before the full nutritional standards come into effect.
Or will we need another Jamie Oliver programme to stimulate further action?
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