His comments follow an expert advisory group's recommendation that all pupils at the country's low-decile schools should be offered free food.
Masterton Primary School principal Sue Walters said some students were coming to school on an empty stomach or without lunch, and said the free food proposal had some merit.
"Part of me thinks it's a good idea because it would solve a lot of the problems for a lot of the kids," she said. "Providing kids with a necessity in life is important. Kids can't learn unless they're fed properly."
But Ms Walters had some concerns and said schools were becoming a "one-stop shop".
Masterton Foodbank co-ordinator Maureen Potts said they handed out about 120 to 140 food parcels a month, mostly to young families. "I think it's very important that children do have food for learning," she said.
Founder and chief executive officer of the Kids Kai Time Charitable Trust, Michelle McArthur, said there was a huge need for food for children: "If they haven't got a full stomach they can't learn."
The charity aimed to feed children in schools.
The free food recommendation was part of the advisory group's Solutions to Child Poverty paper, published last week.
Children's Commissioner Russell Wills said several schools already had similar programmes in place.
"The principals are doing that because they know that kids are coming to school hungry, and hungry kids don't learn.
"The kids don't just learn better, but they relate to each other better, the behaviour in the class settles down and the whole environment improves."
Schools providing meals had also adjusted programmes to suit their individual communities, Dr Wills said.
Dr Wills said his office had yet to hear from the Government about the recommendations.
The facts
* Children living in poverty are deprived of the material resources and income required for them to develop and thrive.
* 270,000 kids, or 25 per cent of New Zealand children, live in poverty, according to 2011 figures.
* 35 per cent of children living in poverty are from families where only one parent works.
* Poverty rates for Maori and Pasifika children are consistently higher than Pakeha children.