Dr Bill O'Connor would like to see more schools stop selling or allowing sugary items to be consumed at school, and switch to water only.
The PM told the throng of Wellington teachers the country's education system is in need of "radical change" but that it "takes time".
Union head Lynda Stuart says there is a real struggle to attract people into teaching, and to keep them there.
Teacher aides are often paid out of the same budget that pays for maintenance and toilet paper.
Pat Newman says schools are "screaming out" for help dealing with the problem, but are being told there's not enough funding.
Māori Development Minister, Nanaia Mahuta, encouraged people to have their say on the draft strategy - with public submissions now open.
Karl Pearce wrote to Massey University vice-chancellor Jan Thomas saying the event could be used as a platform for separatist and supremacist hate speech.
The collapse of two academic institutions has seen a group of students possibly having to leave New Zealand without their diplomas.