The Health Star Rating system just doesn't work for oils

On any given trip to the supermarket you are faced with literally thousands of food products. You want to get the shopping done as quickly as possible, but you also want to make healthy choices. From reading the tiny nutrition information on the back of pack, to being bamboozled by marketing and health claims, it can become impossible to know what to buy.

A good diet has never been more important. When facing an almost overwhelming range of options in the supermarket aisle, consumers look for answers in the Health Star Rating (HSR) system, introduced by the federal, state and territory governments in 2014.

On the surface, the HSR system is brilliant. At a glance we can see a rating of ½ to five stars on the front of pack. Choose the products with the most stars and we can achieve a healthier diet – or can we?

The system is now under formal review. For the most part, it works well and is popular with consumers. However, there are areas that need improvement, and areas where it simply doesn't work at all. Like how some companies manage to secure a high HSR based on the "as prepared" format (how the manufacturer intends for you to consume the product). Enter cereal companies receiving ratings based on a serving with milk.

To hear that the HSR system will be limited to the product "as sold" following the review is a step in the right direction.

Another bugbear of mine is edible oils. As the proposed changes now stand, refined seed oils canola and sunflower will be awarded five stars – the top score. Meanwhile, extra virgin olive oil and avocado oil, both completely unrefined and cold-pressed, will only receive four stars. That would suggest that canola and sunflower oils are the healthier choice, right? If you think that sounds odd, the science backs you up.

Extra virgin olive oil is literally juice squeezed from fresh olives – a gentle process that brings with it nutrients such as vitamin E and an array of healthy phytochemicals. Canola and sunflower oils, by contrast, are refined oils where chemicals, heat, high pressure, deodorising and possibly bleaching are used in production. These processes largely destroy the phytochemicals present in the seeds such that almost none remain in the oil.

So why are these oils getting more stars than extra virgin olive oil? Because the HSR algorithm considers saturated fat alone, as if nothing else matters. The reality is that all three oils are low in saturated fat and to differentiate on this alone is completely misleading.

These examples are exactly why we have to review, update and amend the HSR system to ensure it is achieving what is intended. Small kinks are to be expected with any system, especially one involving the human diet, which is incredibly complex. Creating an algorithm capable of assessing all nutritional aspects of a food or product is practically impossible.

Let's hope the review committee listens and acts to see through the necessary changes to ensure Australian consumers get the correct guidance.

Dr Joanna McMillan is a PhD-qualified nutrition scientist and accredited practising dietitian. She is also an independent nutrition consultant who works with Cobram Estate to help educate consumers and healthcare professionals about extra virgin olive oil.