An Auckland principal says wellbeing and education go hand in hand, after it was revealed the government knew of profound benefits from the free school lunch scheme before it decided to cut funding.
Budget documents released on Thursday also laid out how the scheme resulted in happier and healthier children.
But Associate Minister David Seymour, who was the architect behind the trimmed down scheme - said they were able to do the same while spending less.
At Rowandale School, students enjoyed a balanced lunch as part of the Ka Ora, Ka Ako scheme.
The research behind the findings was supposed to be published in June - but got pushed back.
Rowandale School principal Karl Vasau said the findings didn't come as shock.
"We've seen the benefits for our community and for our students," he said.
"Reports like this, not surprising, the findings that overwhelmingly food in schools supports wellbeing, because it's a no-brainer, and doesn't take rocket science to know that it does."
But despite the government being told of the "profound" benefits to wellbeing - it decided to cut annual funding for the scheme anyway.
It shaved $107 million off it earlier this year.
The trim meant children at intermediate and secondary schools would get a lunch that cost $3 to make.
Vasau said funding cuts were having an impact on many of his colleagues.
"I know it's having a huge impact on my intermediate and secondary school colleagues, who are now facing a cut in funding, and also, there was suggestion of how [they] would provide the lunches," he said.
"Some of the schools that set up kitchens in relation to providing the lunches for their kids and other schools have now got those questions of how it's going to be funded."
Earlier evaluations also found the scheme resulted in happier, healthier children.
But Associate Education Minister David Seymour stuck by his call - and said spending less money was a good thing.
"We're actually improving it," he said.
"To the extent that it's a good thing, we're doing better at that but we're also doing it for less money, which I think has got to be a positive," he said.
He wanted the money for school lunches properly allocated.
"I think wellbeing's important, I also think that when we go to Parliament and appropriate money to use from the tax payer it has to be used for a purpose, and in this case the purpose is education."
Seymour also said the Education Ministry was investigating accusations a teacher had taken lunches from students before eating it themselves.
"In one school South of Auckland, there's been quite acute allegations from a parent that lunches were being taken, children were coming home hungry," Seymour said.
"The parent tried to raise it, there's been some back and forth between the school and the parents."
He said the children had at one point tried to phone their parents to tell them what was happening, but had their phone confiscated.
"There's been quite a fracas about this," Seymour said.
"Teacher's job is to teach right from wrong, hard to do that when the teacher's the one knicking your lunch."
But Seymour provided no evidence.
Co-chair of the Health Coalition Aotearoa and Auckland University professor Boyd Swinburn of the Health Coalition Aotearoa and Auckland University professor Boyd Swinburn said they and others had been supplying the government with examples and evidence about the benefits of the lunches.
"There are multiple, multiple benefits, and the government really does have a stack of evidence on that in front of them when they made that decision."
He said not getting enough food could have lasting consequences.
"By the time kids, New Zealand kids, are age 15, if they have had food insecurity under any form at home, then they are two to four years behind their peers in their educational attainment," Swinburn said.
Karl Vasau said the link between being able to eat well and learn was obvious.
"In order for you to learn, and engage, and take on challenges in your day in school, you need to have the resources, the skills, the knowledge, the food, the energy," Vasau said.
"It is part and parcel, children who are fed well and feel good about what they're eating, and are not hungry, will learn far better than those that aren't."
And his students agreed.
"I can't work properly on an empty stomach," said one student.
"If they didn't bring hot lunch, I'd be cold all day," said another.
"It helps me keep fit an healthy," added a third.