School food charity KidsCan says demand for emergency food supplies in low decile schools has doubled over the past 6 years.
KidsCan CEO Julie Chapman says the percentage of children needing food in schools that are supported by the charity has jumped from 11 per cent in 2011 to 22 per cent this year.
Chapman says the jump has been particularly noticeable in the east of Christchurch where at least 10,000 houses were demolished due to the Christchurch earthquakes.
"Certainly the housing pressures [in Christchurch] have forced a lot of families into situations where they're sharing houses and I think that coupled with increased cost of living is having a real impact."
Linwood North School principal Sandra Smith says the stress on the local community is acute and has resulted in more students coming to school without food than ever before.
"Things have become exponentially more challenging for families in the east of Christchurch," she said.
"There is absolutely genuine poverty in this community that can't be helped by the families that are living in it.
"It's time for the rest of New Zealand to really wake up to the fact that many of our children are not getting the lives that we had when we were children."
Smith says she now relies on food and clothing provided by corporates and charities like KidsCan to ensure her students don't go hungry during the day.
"When you're hungry you can't learn. So for some children who come to school with no breakfast or lunch we're able to provide the food. We're filling a real need," she says.
KidsCan figures show the charity now supports 700 schools and a record 30 thousand children every week across the country.