Education over taxation, is being put forward as the solution to the obesity crisis.

A new report from the New Zealand Initiative pours cold water on the idea of a sugar tax, saying they don't work, and unnecessarily restrict freedom of choice.

Executive Director Oliver Hartwich said it's better to make people aware of their options.

"We have to do more education. Now, a lot of people would say we've been trying this for decades, we've been trying to get people to live a more healthy lifestyle and it hasn't really worked, but that shouldn't stop us from trying better."

Labour's health spokesperson Annette King said education has been tried, and failed.

"When education is used that is a cop out because researchers know that education alone isn't going to change behaviour particularly in health."

King said the major problem is the loading of sugar into processed food.

"What we could do relatively quickly is to require the reduction of the added sugar that's put in processed food."

Hartwich said a sugar tax could be the beginning of a slippery slope.

"Once we let Government get away with introducing new regulations and taxes for which no proper cost benefit analysis has been undertaken, we are basically setting a precedent for policy making."