Make Lunch says more kids than ever needed food during the recent February half-term, with demand so high that waiting lists had to be brought in.
The charity provides hot meals free of charge to primary school children at 64 different projects across the UK. It says that the increase is child hunger is not new, but simply revealed by the growing number of meals the charity is able to provide.
It's prompted the All Party Parliamentary Group on Hunger to order an inquiry into the issue.
Around 1.2 million children in lower income families are entitled to free school meals, but the increasing demand reported by Make Lunch suggests they struggle to eat properly outside of term-time.
A poll by Yougov recently found around 1 in 3 parents has skipped a meal in order to make sure their child eats properly.
Speaking on Premier's News Hour Rachel Warwick, a Christian and founder of Make Lunch, said: "We've been ignoring the issue, I think, because there's been no provision for these families in school holidays. We're serving in more places than we ever have.
"One of the things that we really prioritise at Make Lunch is advocacy... We're emailing MPs, we're inviting them to our clubs, just to constantly challenge the government and say: 'this is what we're doing about this problem - what are you doing about this problem?"
A government spokesperson said: "Tackling child poverty and disadvantage is an absolute priority for this Government. Thanks to our reforms there are more people in work than ever before and the number of children growing up in workless families is at a record low – down by 557,000 since 2010."
Listen to Premier's Antony Bushfield speaking to Rachel Warwick: