Have you noticed this health star rating on the bottom left hand corner of your food? Photo: Supplied
Australia are rethinking their health star rating system, and according to health experts in New Zealand, it's time we followed suit.
Health star ratings fall on a scale from 0.5 to 5 stars, with ratings based on the overall health of a product. This is determined by the amount of sugar, salt, fat, fibre, protein, fruit, vegetable, nut and legume content, which is popped into the official Health Star Rating Calculator to determine a star rating.
Both New Zealand and Australia currently follow the same system, subject to the same flaws. The most pressing issue is that health stars are a voluntary scheme that's completely self-regulated by producers who can pick and choose which products they apply the ratings to.
The logic is that the more stars a product has, the healthier it is than something with fewer stars. However the stars don't indicate the overall health of products - it's more a comparative rating across foods in a similar category, meaning you can compare Weet Bix and porridge to a sugary cereal, but not a breakfast cereal to a can of fruit, for example.
On Wednesday, the ABC reported that Australia's health star ratings system could soon be subject to a government overhaul. It would mean mandatory ratings, more onerous labelling on packaged products, and restrictions on marketing.
Dr Rajshri Roy, an honourary senior lecturer in nutrition at the University of Auckland, says New Zealand's health star ratings system is useful in some ways, but a similar overhaul could improve it vastly.
"There are some advantages to it, it's a quick visual guide, easy to understand, it could potentially incentivise food manufacturers to reformulate their products if they want a higher star rating, but the way it's implemented currently, it's not doing what it's supposed to.
"Even if we do educate consumers about the fact that [the ratings] are within a category, and it's self-regulated by the food industry, there will never be proper comparison within the category, because some products will have it, and others won't ... dieticians, we've been advocating to policymakers for comprehensive approaches, and that includes having these systems in a mandatory nature so there's no potential for misleading ratings."
Health star ratings are a quick visual guide, but they don't give consumers complete information, Dr Rajshri says. Photo: 123RF
According to Consumer NZ senior writer Belinda Castles, only 30 percent of the intended products currently display health star ratings, which is "not enough products for it to be meaningful or useful for consumers".
Moreover, health stars are only for packaged items - you won't find them on fruit, vegetables or meat. Castles says it's important to stress that "healthy" packaged foods aren't a replacement for a balanced diet.
"You don't wanna be comparing a packaged high sugar product like a muesli bar with fruit and vegetables... health stars are calculated on the overall nutritional content of a food, so healthier aspects like fibre or protein can offset the not-so good nutrients like the sodium and saturated fats and get a higher rating ... people still need to sometimes check the nutrition information panel and the ingredients list to see what's actually in a product."
Health stars don't consider serving size, or the additional additives and preservatives of a product. Dr Rajshri says the system doesn't adequately distinguish between types of fats and sugars either, meaning "some highly processed foods tend to get higher stars because of this lack of differentiation".
But it's not just health experts who have questioned the effectiveness of the health star ratings system. In October 2023, National Party MP Shane Reti (now the Minister of Health) suggested the current system is "no longer fit for purpose" and should be scrapped entirely and replaced with a new one.
National MP Shane Reti says it's time to scrap the health star ratings system. Photo: RNZ / Reece Baker
So what can we use instead?
The UK uses a traffic light food labelling system, with red, amber and green colour coding applied to nutritional information. At a glance, it can tell consumers if the food has high, medium, or low amounts of fat, saturated fats, sugars and salt.
Dr Rajshri says a similar system in New Zealand could "potentially" work.
"The UK's traffic light labelling can potentially provide consumers with bit more of a detailed guideline... the use of colour coding indicate levels of each nutrient... whereas something simple like the health star ratings system can become too simplistic... the problem is that we don't have enough public health efforts to improve the nutritional literacy of consumers so they better understand these front of pack labels like health star ratings."
Castles suggests it's less about scrapping the current system, and more about revamping it to meet consumer needs.
"I don't think there's any perfect system, I think a lot of health experts would like to see some sort of colour coding incorporated into the health star ratings system, so for example it might show if a product's high in sodium and if you're concerned about that, it might colour code that icon red... I think definitely making it mandatory so that companies can't choose to only put it on their products with a high rating, but then that colour coding component would help consumers as well."