A fifth of pupils in Devon are eligible for free school meals, recent figures show.
It comes as the Government announced plans to expand free school meals to more pupils in England, adding it would make 500,000 additional children eligible.
Charity Feed Britain said the expansion will help a significant number of children to "break free of the hunger trap", but called on the Government to make eligible pupils' registration to the scheme more straightforward.
Department for Education figures show 20,508 (21%) of the 99,432 pupils in Devon were eligible for free school meals in January.
This was up slightly from the previous year, when the proportion stood at 20%, and the highest figure since records began in 2015-16.
Across England, an additional 77,700 children became eligible for free school meals last year, taking their total to more than 2.17 million in January.
It means 25.7% of pupils were eligible then – up from 24.6% a year earlier.
Last week the Government announced plans to expand free school meals to all households in England that claim universal credit from September 2026.
Currently, households on universal credit must earn below £7,400 a year (after tax and not including benefits) to qualify for the scheme.
The Government said the expansion will make 500,000 additional children eligible and save parents nearly £500 every year.
It also suggested the change would lift 100,000 pupils across England out of poverty.
Andrew Forsey OBE, national director of Feeding Britain, said: "The Government's decision to expand eligibility to a broader group of children in poverty, whose parents work for low wages, "will help hundreds of thousands more children break free of the hunger trap.
"Yet all too many children remain trapped, despite being eligible, as they're not registered for their free school meal entitlement.
"As a next step, to help every child break free, the Government needs to introduce a policy of automatically enrolling all eligible children for free school meals.
"This would put our country firmly on track to abolish child hunger."
Stephanie Slater, founder and chief executive at School Food Matters, welcomed plans to expand access to free school meals, saying it will "replace the draconian eligibility criteria".
She said: "For children living in food-insecure households, the value of a guaranteed hot, nutritious meal each school day cannot be overstated.
"This extension means many more children from struggling households will have access to that vital support too."
She added the benefits of expanding access to free school meals "go far beyond tackling child hunger".
"We know from all the evidence that this is one of the best investments a government can make – not only for children’s long-term health and learning but for the economy too," she said.
"Teachers often tell us they can see the difference in children who come to class after having a nutritious meal, as they are more focused, energetic, and ready to learn."
A DfE spokesperson said: "Through our Plan for Change, this Government has taken a historic step to tackle the stain of child poverty and spread opportunity – extending free school meal eligibility to all children in households on Universal Credit.
"This means over half a million more children will be able to access free meals from the 2026 school year, lifting 100,000 children completely out of poverty – and we will launch an upgraded eligibility checking tool next year to make it simpler than ever for parents to see if they can benefit.
"This forms part of our wider plan to put money back in the pockets of working families – with parents also set to benefit from our free breakfast club rollout and school uniform cost cap, helping them save up to £500 a year."