MPs are urging ministers to ban processed foods from school dinners in the wake of TV chef Jamie Oliver's "crusade" to improve children's diets.
MPs are worried about the negative impact of a poor diet
They say they are appalled that each school meal costs less than 45p - a quarter of the cost of prison dinners.
The cross-party group of 46 MPs have signed a Commons motion praising the chef's "Feed Me Better" campaign.
They welcome government efforts to introduce minimum standards but say more could be done.
The call come just days after the Local Authority Caterers Association argued that more cash was needed to make sure Mr Oliver's "crusade" did improve England's school dinners.
The TV guru has replaced all processed foods at Kidbrooke School in Greenwich, London, with freshly cooked meals.
He has said government funding should rise from 37p a day per pupil to 50p and has described much of the processed food served to children as nutritionless "rubbish".
Jamie Oliver is trying to wean children off pizza and chips
The MPs, led by Ulster Unionist Roy Beggs, say they are worried about the increase in child obesity, and what they call the "negative effects that a poorly balanced diet has on the concentration, behaviour and social skills of pupils".
They said they welcomed the government's introduction of tougher minimum standards to ensure there is less sugar, fat and salt in school meals, but said more could be done.
Mr Oliver's efforts at Kidbrooke - featured in the Channel 4 series Jamie's School Dinners - were not popular at first with its pupils, with canteen use actually declining after his arrival.
However, the likes of fish pie, lemon roasted herb chicken and chilli beef fajitas eventually saw children returning to school dinners.
Kidbrooke's head teacher, Trisha Jaffe, told the BBC News website: "The fact that Jamie is a gourmet chef doesn't interest the pupils.
"They are interested in what they like. You have to get them used to a different kind of eating."
Greenwich has decided to implement similar healthy eating initiatives at all its schools.
Mr Oliver recently met Education Secretary Ruth Kelly to discuss catering standards.
She has promised that guidelines on the nutritional value of processed foods such as beef burgers and sausages will be introduced into schools in England from September.
Parents and the food industry are also to be consulted on standards.