Health star ratings: Why researchers say it’s time to rethink them

• Researchers back calls to make voluntary health star ratings mandatory, among other measures to fight obesity.
• Just 30% of intended supermarket products have them - well short of 70% target set for late 2025.
• A new study finds they made little improvement to nutrition when introduced a decade ago.

There are fresh calls to overhaul the star ratings we use to help hunt out healthy food at the supermarket, with a new analysis showing they brought little improvement when they were first introduced.

The voluntary ratings, which rank and label foods on a scale of 0.5 to five, were brought in a decade ago and recently toughened for products high in salt and sugar.

While used by most shoppers, they’ve been criticised by nutritionists and consumer advocates for being sometimes misleading, self-regulated and covering only a third of the products they’re intended to.

That’s well short of a set target for the ratings to cover 70% of products by the end of next year - and both Australia and New Zealand are already considering making them mandatory for companies.

Now, University of Auckland researchers have argued New Zealand could be going even further in encouraging food companies to make their products healthier.

That’s come with a study, published in the journal BMC Medicine, that analysed nearly 18,000 packaged products from 35 Kiwi companies over the first five years of the rating system.

It found on average, products scored just 2.7 out of five - in line with what’d been found in earlier research here and overseas - and that there’d been just a slight improvement over the period.

That lift equated to just 0.08 points out of five, the rating typically given to fresh fruit and vegetables.

It partly owed to a drop in total sugar content - seen mainly in cereal and confectionery products - and also from companies producing meat alternatives, sauces and spreads.

The authors found other unhealthy nutrients like sodium and saturated fat remained largely unchanged.

Study lead author Dr Leanne Young said the observed increase over the five years was a step in the right direction, but it was “unlikely to make a difference to improving the diets of New Zealanders”.

She and her fellow authors argued more action was now needed from regulators, including mandating ratings, but also Government-led reformulation targets and a sugary drink industry levy like what has been introduced in the UK.

Health star ratings found on packaged supermarket products are taken note of by around eight in 10 Kiwi consumers, with a similar proportion of respondents saying they completely or somewhat trusted the system.

“A study has found that it had an effect on obesity among 10 to 11-year-old girls, with the largest declines seen in the most deprived children,” she said.

“It was estimated to prevent 5000 cases of obesity in this group.”

Young also cited Chile’s mandatory warning labels on foods high in sodium and sugar, as well as mandatory sodium targets in South Africa and Argentina, as evidence-based policies the Government should be considering to improve Kiwis’ nutrition.

A spokesperson for Health Minister Dr Shane Reti - who last year suggested altogether scrapping and replacing the ratings - didn’t say what specific measures the Government was looking at.

But advice on “potential priority actions” to address poor nutrition was expected within weeks.

New Zealand Food Safety (NZFS) acting deputy director-general Jenny Bishop noted the health star ratings had recently been improved to penalise foods and drinks higher in total sugar and sodium.

Despite their flaws, new survey data also showed the ratings were still utilised by around eight in 10 consumers, with a similar proportion of respondents saying they completely or somewhat trusted the system.

“This is a clear message to the food industry that consumer demand for [the health star ratings] exists and that food producers who use [them] will benefit,” Bishop said.

NZFS was meanwhile working with the food industry and retailers to improve the voluntary uptake of the ratings and was about to launch a new awareness campaign aimed at informing consumers on how to use them.

“We know that people probably already understand that ice cream is less healthy than apples,” Bishop said.

“But if you want to buy ice cream, the [rating] system is there to help you make a healthier choice between different ice creams.”

NZ Food and Grocery Council chief executive Raewyn Bleakley meanwhile said the group still fully supported the rating system and reformulation programmes.

“We actively engage with food manufacturers on these initiatives, and we’re seeing good progress in the right direction.”

Jamie Morton is a specialist in science and environmental reporting. He joined the Herald in 2011 and writes about everything from conservation and climate change to natural hazards and new technology.

Sign up to the Daily H, a free newsletter curated by our editors and delivered straight to your inbox every weekday.