The star system assesses the overall nutritional profile of packaged food, assigning ratings from ½ star to five stars as a method to compare similar food items.

However, because of the way the stars are awarded, shoppers can still end up with an unhealthy product in their trolleys.

The George Institute for Global Health, which is researching the star system, today released a paper on its uptake by companies and understanding by consumers.

Introduced four years ago, the government-initiated, voluntary rating system appears on only one-third of packaged products throughout Australia, the institute found.

Of those products that displayed their star ratings, most were at the upper end of the ranking system.

Not all is as it seems

While Deakin University Professor of Public Health Nutrition Mark Lawrence agrees with the concept of an easy-to-read health rating system, he says there are flaws with the way the Health Star Rating is implemented.

Professor Lawrence says the way the stars are calculated ignores the food product itself and concentrates on its nutrition – meaning it is out of step with the current and accepted nutritional science knowledge base.

“The rating doesn’t differentiate if these [the nutrients] come from a healthy food or a junk food,” he tells The New Daily.

“What we call discretionary foods – junk foods – are getting very high ratings of stars.”

The star system has been criticised in the past, most notably for awarding Milo a 4.5-star rating, a move it was forced to retract after lobbying from the health industry.

Professor Lawrence references muesli bars, which can regularly be given a four-star rating, but are brimming with high sugar levels and are highly processed.

“It’s giving (foods) a healthy halo,” he says.

“People compare two products’ star ratings and think, ‘Oh this one is good’ – when really it’s only good relative to the other one, which is really bad.”

Ignoring the real problem

One of the key issues contributing to Australia’s obesity epidemic is the rise of highly processed or ultra-processed foods, Professor Lawrence says.

His view is backed up by US research that this month showed people who consumed more ultra-processed foods gained more weight than people who followed less-processed diets – even though their nutritional intake was on par.

“It [this research] highlights a major nutrition science weakness with the health star rating system – it’s based on the amount of a limited number of nutrients in a food regardless of first determining whether the food is nutritious or ultra-processed,” Professor Lawrence says.

So until the Health Star Rating system is overhauled (the Government is currently undertaking a review of the system, with recommendations due at the end of June), what’s the best way for Australians to shop healthy?

“The simple advice is: More often than not, look for less-processed food,” Professor Lawrence says. “Avoid ultra-processed food, aim for minimally processed – and a variety of it.”

This article was first published on The New Daily.