Some British children will go back to school skinnier this week – not because they've been running around all summer, but because they haven't had enough to eat.

The Trussell Trust and Kellogg's have released a report saying that 39 per cent of teachers think that pupils don't eat enough over the summer holidays.

There are 1.2 million children who receive free school meals during term time, and an estimated 3.5 million children living in poverty in Britain. In the absence of school meals, many of these children's parents struggle to feed their children.

Children are in school for 190 days, and out of school for 170 days, and the six-week summer holiday is a significant burden.

Teachers estimate that one in eight pupils is not getting enough to eat during the school holidays, and they start school noticeably thinner.

The Trussell Trust, the Christian organisation that runs most of Britain's foodbanks, saw a significant increase in the demands on foodbanks during the summer break last year and anticipates similar findings this year.

Numerous organisations and schemes have tried to step in to fill the breach, with breakfast and lunch clubs being set up around the country.

MakeLunch is one of them, with kitchens in 30 locations around the UK – using churches and school halls to serve lunch to 6,500 children this summer. Including the other holidays this year, the total number of children served will be around 10,000.

MakeLunch director Rachel Warwick started the scheme after watching a documentary about poor children in Britain. "I worked as a teacher but I didn't think about what happened to the children out of school term. It was one of those light bulb moments," she says.

The charity aims to ensure that children are able to get a hot, nutritionally balanced meal once a day during the holidays.

"Obviously a six-week holiday can be quite expensive. It makes a lot of difference to the shopping bill," says Donna, a parent of three and a volunteer at a lunch club in Essex.

Bringing people together during the summer hoildays isn't just about thefood, it also helps to build communities, and many of the MakeLunch kitchens encourage families to eat together, as well as providing fun activities for the children.

MakeLunch has seen an increase in the number of people coming for lunch this summer, as their reputation has grown. The number of people attending the Essex kitchen has doubled over the last six weeks.

It takes time to build trust, says Warwick, who understands that parents are afraid that if they come, and admit they are struggling, social services might take their children away.

"A lot of people don't turn up because they're too proud," says Donna. "But they don't make you feel like that, it's more of a community thing."

Kellogg's and the Trussell Trust have also joined together to set up holiday breakfast clubs around the country.