The prime minister's chief science advisor says sugary drinks have no place in a child's diet but has stopped short of calling for a tax or ban on them.
Sir Peter Gluckman is leading the World Health Organisation's commission to end childhood obesity.
He told Radio New Zealand's Kim Hill the commission was investigating how to advise governments on proper nutrition from pregnancy through to a child's teenage years.
"I think sugary drinks are a real concern. Many countries and many companies are banning them from schools, as they should. I think that the issue of whether fiscal measures are needed to reduce the intake is something that's a real - something that has to be thought about."
He said even sugar free drinks with alternative sweetners were also contributing to obesity.