Experts at loggerheads over NZ's decision to join star rating system
Nikki Kaye, the country’s minister for food safety, announced last week that New Zealand food manufacturers would adopt the Healthy Star Rating system, but on a voluntary basis.
Under the system, food and beverages are given a rating between half-a-star and five stars, based on how healthy they are.
Traffic light labels better
Not too long after the decision, University of Otago researchers questioned the likely effectiveness of the system, pointing to a recent study that suggested star ratings might not be the best option for consumers.
Dr Ninya Maubach, a researcher at the university, recently led a study that compared three front-of-pack nutrition labels—star ratings, daily intake guides, and multiple traffic light labels—as well as the back-of-pack nutrition information panel.
The research examined consumers’ preferences for fruit mueslis with different nutritional profiles in an experiment involving over 750 New Zealanders last year.
According to its findings, consumers made similar choices towards the healthiest muesli option when the packaging featured either the star ratings or multiple traffic lights. At the same time, the latter was found to better help consumers identify and avoid less healthy brands of muesli.
Participants also rated the healthiness of the options tested, and were significantly better able to differentiate between nutrition profiles when these featured colour-coded traffic lights.
“These findings show most people can identify healthy products with either the stars or traffic light labels. However, a traffic light label appears much more likely to help people distinguish less healthy choices. If we want to use labels to reduce obesity, we need a label that promotes quick identification of unhealthy products,” said Maubach.
Maubach also called on the government to make interpretive front-of-pack nutrition labels mandatory, rather letting companies opt-in.
“A light-touch regulatory approach that relies on voluntary action is not in the consumer’s best interest. All packaged foods should feature the same nutrition labels so shoppers have a fair chance to understand foods’ nutritional merits.”
A positive step
However, Prof. Cliona Ni Mhurchu, a nutrition researcher at Auckland University, said the introduction of interpretive, front-of-pack nutrition labels was a positive step for New Zealand.
“We have high rates of obesity and diet-related disease in this country and simple, interpretive, front-of-pack nutrition labels have been identified as potentially one of the most cost-effective ways to counteract these problems,” she said.
According to Mhurchu, evidence has shown that people struggle to use and understand New Zealand’s current back-of-pack nutrition information panels.
“Research has also shown that people can work out what foods are healthy or unhealthy more easily when using interpretive nutrition labels, like he UK’s traffic light labels.”
Though she cautioned that any nutrition label would only have a positive effect on diets and health if it was widely available and not just in niche categories or on a small number of brands.
“The new system is voluntary so it is essential that there be an independent review of progress of implementation after a reasonable period, such as after two years,” she said.
“If there is not widespread uptake at that point. New Zealand should consider following the example of Australia, [which plans to] make the system mandatory unless voluntary uptake is extensive.”