Most packaged food on sale in NZ is unhealthy - report

New research has highlighted the vast amount of unhealthy food on offer at supermarkets.

University of Auckland experts analysed 13,000 packaged food items as part of the inaugural State of the Food Supply report. Its author, Sally Mackay, says they found nearly 70 percent could be classed as ultra-processed.

"They're ready-to-eat or drink items, they're based on refined substances, and they often have added salt, sugar and fat, and other additives," she told Newshub.

She wants Health Star rating labels to be made compulsory.

"The Health Star ratings are quick and easy to use - it's having a look at one number. If they were on all products, it would help consumers."

The report also found more than half of items on sale in supermarkets are discretionary foods - meaning they are not necessary.

"A poor diet is the leading cause of early death in Aotearoa New Zealand, accounting for nearly 20 percent of illness and premature death."

Fifty-nine percent of all food on sale had a rating of three Health Stars or fewer. Dr Mackay says food companies have a responsibility to look at sugar and sodium levels. 

"I know a lot of the food companies are starting to do this, but there's still quite a long way to go in improving the formulation of those products."

Only three companies' range had an average 3.5 Health Star rating or above - Sanitarium, McCain and Sealord. 

"Companies like these show it's possible to have healtheir products within a category," said Dr Mackay. "Ultimately, it would be great to see consumers buying more fresh wholefoods. But realistically there will always be a need for packaged food, so it needs to be as healthy as possible."

Only one-fifth of eligible products even had a Health Star rating. 

"Consumers have the right to know the healthiness of the products they're buying."

The State of the Food Supply report will be released annually.