Taxing sugary products will not prevent the spread of the disease, Diabetes New Zealand says.
The comment came at the launch of its first awareness month in Auckland this morning.
Chief executive Steve Crew said 250,000 people had diabetes, and one in four risked developing it.
A so-called sugar tax had attracted a lot of attention but would not fix the problem, he said.
"You can't tax sugar like you can tax tobacco. Tobacco isn't in everyone's everyday life.
"Addressing obesity needs to be more of a holistic approach. It should be about education, empowering people to make better choices."
There was a widespread lack of knowledge about diabetes despite it being one of the country's biggest health issues, Mr Crew said.