"If it does come to the fore, we contact parents and have conversations - we do it in a positive way."
His school is part of the Fonterra milk in schools programme and provided Milo in the morning and milk in the afternoon.
A ban on sugary drinks in New Zealand would be very hard to govern, he said. "If you ban something there's always another way of other people trying to make sure there's supply for those sort of things."
In 2012, a coroner's report found Invercargill mother-of-eight Natasha Marie Harris, 31, died of cardiac arrhythmia caused by poor nutrition and the effects of caffeine.
An inquest revealed Ms Harris drank only Coke and consumed between six and 10 litres a day.
Gerhard Sundborn, from Auckland University, has proposed a strategy for sugar-sweetened drinks in New Zealand. Based on proposals which aim to see New Zealand smokefree by 2025, the sugary drinks equivalent would see a heavy decrease in the amount of sugar Kiwis consume.
"There's no denying obesity has become an epidemic. By regulating the sugar content in beverages we'll be taking the first step to combating this global health problem," Dr Sundborn said.
Initiatives to tackle obesity had proven ineffective - data suggested our sugar intake was growing, he said. "Just like tobacco, evidence also suggests many New Zealanders are addicted to sugar. People coming off a high sugar diet can often experience withdrawal symptoms, which is another reason these drinks need to be regulated."
New Zealand Nutrition Foundation dietitian Sarah Hanrahan said interventions such as taxing drinks were worth considering.