One in ten parents “don’t know” what their child has for school dinner.

Parents could be jeopardising their children’s oral health by being unaware of what they are having for lunch, according to the findings of a new survey.

A poll conducted oral health charity the British Dental Health Foundation discovered almost 10% of parents don’t know what their child eats during school hours. More alarmingly, a further one in 20 parents claim their child eats fast food on their lunch break.

The majority of parents were aware of what their child was eating with four in every five sending their child to school with a packed lunch or with arrangements for them to eat at the school canteen.

More than 3,100 primary schools — one in five find it hard to deliver cooked lunches because they lack proper kitchens and cannot afford them.

They are forced to buy-in pre-prepared meals and either keep the lunches warm or heat them up — in some cases with a microwave — on site in mini-kitchens.

In some cases, the pupils will have to eat sandwiches at a desk because there is not enough space for all the children to eat together.

All pupils at infant schools in England now get free school lunches.

This — for children in reception, year one and year two — will save parents about £400 a year per child.

Targeting infants will ensure “every child gets the chance in life they deserve, teach healthy eating habits and boost attainment”, a government spokesperson said.

Head teachers are being encouraged to take a lead on food at their schools. The plan outlines the importance of helping them to achieve the goal.

Last year, the Secretary of State for Education asked Henry Dimbleby and John Vincent to work with schools, councils, caterers, parents and government to set out how to increase the number of children eating good food in schools.

The actions set out in the plan include £16.1 million of new money to help prove that better school food can have a significant impact on children’s health and attainment.

£3 million is being made available to ensure healthy breakfasts are available for thousands of children who arrive at school hungry. The new initiatives are part of the new school food plan to encourage students to use breakfast clubs.

The government’s review of school meals in England was published in July 2013. The review was led by restaurateurs Henry Dimbleby and John Vincent and supported by an expert panel including the Children’s Food Trust.

The new school food plan is effective from January 2015.

The school food plan, designed to promote healthy eating, will be mandatory for local authority schools, new free schools and schools that convert to academy status.

The Department for Education said the previous rules had done “much to improve school food” but “were complicated and expensive to enforce”.

The revised regulations are intended to allow school cooks more flexibility and include:

• one or more portions of vegetables or salad as an accompaniment every day
• at least three different fruits and three different vegetables each week
• an emphasis on wholegrain foods in place of refined carbohydrates
• an emphasis on making water the drink of choice
• limiting fruit juice portions to quarter pints (150ml)
• restricting the amount of added sugars or honey in other drinks to 5%
• no more than two portions a week of food that has been deep-fried, batter-coated or breadcrumb-coated
• no more than two portions of food that include pastry each week
• a portion of milk (lower fat and lactose reduced) to be made available once a day

The following general principles apply in new food legislation:

• For children, eating in school should be a pleasurable experience; a time spent sharing good food with peers and teachers. It is the one time in the day when a school comes together in an informal, relaxed environment.
• The new school food standards are intended to ensure that children get the nutrition they need across the whole school day.
• Chefs, cooks and caterers should also be aware that these standards relate to the nutritional nature of the food served. It is just as important to make the food look good and taste good.
• Wherever possible, foods should be prepared in the school’s own kitchen from fresh, locally sourced ingredients.

Almost a quarter of a million children registered for free school meals are not receiving them. Figures from January 2013 indicate 1.3 million pupils registered for free school meals; a key measure of UK poverty. Of these, only 82.7% actually took up the dinners, meaning many school children were not eating the free meals for which they were registered.

The Children’s Food Trust is calling for action to ensure poor children do not miss out on nutritious food during the school day.

A sample poll of school staff by researchers has suggested a continued rise in the number of children on free school meals. A third of those surveyed said they had seen a rise in the past five years. Most blamed the economic downturn and rising unemployment.