Making healthy food cheaper and upping the price on potato chips and fizzy drinks could save lives, a new study claims.

Research by Auckland and Otago Universities shows the government could save thousands of lives with taxes on unhealthy foods and subsidies on healthier ones.

LISTEN TO DR JULIA PETERS TALK TO JACK TAME ABOUT TAXING UNHEALTHY FOODS ABOVE

The research found that 1500 lives a year could be saved if a 20% tax was introduced on saturated fats, while the same tax could be applied to dietary salt and 2000 deaths would be "prevented or postponed".

The study also found that a subsidy for fruit and vegetables could save around 560 lives in the future.

Maori and low-income New Zealanders would benefit most from the taxes. Study leader Cliona Ni Mhurchu said these groups experience higher rates of obesity and higher death rates from heart disease, cancer and diabetes.

"Taxes are likely to be much more cost-effective than education and exercise programs and that's because they do have a large impact on health and they can prevent a large number of deaths," she said.

"They're also more likely to change in response to prices, so overall the benefits would be greatest for those groups."

With childhood obesity alone, one in nine children are considered overweight according to Ministry of Health figures, while one in five are classified as obese. The number of obese children has increased within the last 10 years from 8% to 11%.

Those figures have earned New Zealand a third-highest ranking in the OECD for childhood obesity.