Taxing fatty and salty foods while offering subsidies on fruit and veggies would prevent thousands of early deaths, research says.
The study by Auckland, Otago and Oxford universities said Maori and low-income New Zealanders would be most likely to benefit because they experience more diet-related disease and are more responsive to changes in food prices.
A computer macro-simulation model tested the effect of the taxes and subsidies, Professor Cliona Ni Mhurchu says.
The model was based on household food expenditure, consumer demand in response to price changes, population mortality rates, and known links between diet and disease.
A combination of taxes on unhealthy foods and subsidies on healthy foods could prevent or postpone a considerable number of early deaths in New Zealand, Prof Ni Mhurchu said.
"Our study adds to the growing body of evidence that food taxes and subsidies should improve population health and reduce inequalities, although there are uncertainties around industry response to such polices and consequent effects on health gains."
The research assumed an instant effect of taxes and subsidies on death rates, but it would take many years for the reduction to be visible due to delays between changing diets and changes in disease rates, collaborator Professor Tony Blakely said.
"Nevertheless, potential future health impacts are large."
Health-related food taxes and subsidies were likely to be highly cost effective, compared with measures such as weight reduction or education programmes, he said.
Nearly one third of adults and one in 10 children in New Zealand are obese.
These rates are highest among Pacific (68 percent) and Maori (48 percent). Those living in deprived areas are also more likely to be obese.
Lives saved by taxes and subsidies: