A stocktake of New Zealand's supermarket shelves shows most packaged food is heavily processed and unhealthy.
Experts from the University of Auckland and George Institute in Global Health in Australia analysed 13,000 packaged items to produce the first New Zealand State of the Food Supply report .
They found 69 percent of products were "ultra-processed" ready-to-eat foods.
Meanwhile, 59 percent had low food-star ratings out of five and some products didn't have a star rating label at all.
One of the authors of the report, University of Auckland research fellow Dr Sally Mackay, said ultra-processed foods are those that had added salt, sugar or fat and often many other additives.
Dr Mackay said rating labels should be mandatory so consumers could make informed decisions about the products they bought.
She said the uptake of the health star rating was too slow and companies needed to hurry up.
"Getting healthier foods on the shelves makes it easier for consumers to make a healthy choice, which is key to curbing the obesity epidemic and diet-related ill health," she said.
Dr Mackay said for any substantial change to happen government intervention was needed in setting targets to lower salt, sugar and saturated fat content.
The study found only three companies - Sanitarium, McCain Foods and Sealord - had a higher mean rating of 3.5 or above.
Meanwhile, 79 percent of breads and 68 percent of breakfast cereals had a star rating at or above 3.5.