New Zealanders who do not have enough access to nutritious and affordable food have higher levels of distress than people who are well-fed, a new study has found.

Researchers at the University of Otago's department of public health in Wellington looked at statistics and a survey of 19,000 people to study food insecurity, which is the lack of access to safe, nutritious and affordable food.

Researcher Kristie Carter and her colleagues found food insecurity not only had an impact on nutrition and physical health, but also on the mental health of New Zealanders.

"What we found is that people who are food insecure report higher levels of psychological distress, compared to those who have enough food to eat," she said.

"The results of this study add further impetus to reducing food insecurity in New Zealand by implementing policies that enhance food security for thousands of at-risk households, particularly in light of rising household and fuel costs."

When socio-economic factors such as income and education were taken into account, researchers found food insecure people had a significant 90 per cent increase in risk of higher levels of distress.

The study drew upon the Survey of Families, Income and Employment, which surveyed 19,000 adults over 2004/05, as well as socio-economic and health data from Statistics New Zealand.

Researchers broadly classified people as food insecure if in the last year they had used food banks or grants, had to buy cheaper food to pay for other things, or often went without fresh fruit and vegetables.

That accounted for 16 per cent of those surveyed.

The findings were consistent for men and women, but women reported higher levels of distress. Food insecure men were 60 per cent more likely to suffer distress while women were 110 per cent more likely to.

Psychological distress was evident in younger people, non-Europeans, solo parents, people living in multi-family households, low socio-economic groups and people with poor health.

The study was funded by the Health Research Council as part of the university's health inequalities research programme.

Responding to the findings, Labour's associate health spokesman Iain Lees-Galloway said a "rampant increase in the cost of living" was creating long term health problems that would cost the country financially and socially if the Government did not step in.