Food star ratings: A guide to healthy eating, clever marketing or just out-of-date science?

Food that makes us healthy is not as profitable as many foods on supermarket shelves, no matter the food star rating.

One of the ways we are told to choose healthy foods is to read the label and check out the food star rating. Is it an edible four or five-star food or an unhealthy ultra-processed blob of empty calories?

Sensible folk with the resources to go past the price ticket need this information.

Food information on the packaging is often provided in the smallest font size possible on the back of the packet. If you’ve left your glasses at home or don’t have time or inclination to interpret the nutrition information panel or the ingredients list, you can check out the stars in the typically bold, colourful graphic on the front.

In Australia, the food star rating is usually displayed in ½ star increments, indicating which foods are better nutritional choices; the more stars displayed, the healthier the food.

The manufacturer determines the number of stars using an algorithm—the Healthy Star Rating Calculator—provided by the Federal Government and developed in consultation with Food Standards Australia New Zealand and other technical and nutrition experts.

The official description of the food star rating is 

a front-of-pack labelling system that rates the overall nutritional profile of packaged food and assigns it a rating from ½ a star to 5 stars. It provides a quick, easy, standard way to compare similar packaged foods. The more stars, the healthier the choice.

The government has not allocated resources to calculate the rating themselves, so they make food manufacturers and retailers responsible for the correct and accurate use of the food star rating calculator and for truthfully displaying nutrient information, the consistency of information between the food star rating and the nutrition information panel.

Full on self-regulation.

We haven’t unpacked the algorithm based on the quantity of energy (kilojoules), saturated fat, total sugars, sodium, protein, dietary fibre, fruit, vegetables, nuts and legumes in the product. 

The government website is opaque on the details but the calculator runs as a spreadsheet in Excel, so it is most likely a direct additive or multiplicative model to rate ingredients and amounts.

The premise for the food star rating is to provide consumers with information on

Choosing foods that are higher in positive nutrients and lower in risk nutrients that are linked to obesity and diet-related chronic diseases; (saturated fat, sodium (salt), sugars and energy), will help contribute to a balanced diet and lead to better health.

Australian Government

A sound premise but heavy with assumptions around risk and the correlation between food and health.

We will come back to this one.

Meanwhile, let’s see what the manufacturers do with the food star ratings.


Clever marketing with food star ratings

Putting the food star rating on your product is not a legal requirement so a manufacturer can choose whether to use it. So you may not be surprised that it is not included where the algorithm will give the food a low score.

Have a look at the Star Ratings given to these three products in the image below.

As you can see the algorithm has awarded a low rating to a product humans have been eating for thousands of years that contains cream, water and salt and a high score to a product with a long list of ingredients, including preservatives, hydrogenated vegetable oils and ‘natural butter flavour’. The ‘buttery blend’ and the ‘spread’ also have added nutrients; butter naturally has these and more.

Stars are used here for promotion rather than as a guide to healthy nutrition.


Out-of-date science 

In Australia, the algorithm used to determine how many healthy stars a product gets is based on the Australian Dietary Guidelines. These guidelines, released in 2013, recommend avoiding saturated fat, added salt and added sugar.  

Butter is more than 60% saturated fat and is often salted. So the reason that butter gets such low food star ratings is that saturated fat has, in the past, been linked to heart disease. However, this evidence is equivocal.

A 2020 review of the latest science, including several meta-analyses, by senior researchers from several institutions and published in the Journal of the American College of Cardiology concluded:

“Several foods relatively rich in SFAs (saturated fats), such as whole-fat dairy, dark chocolate, and unprocessed meat, are not associated with increased CVD (cardio-vascular disease) or diabetes risk”. 

Astrup, A., Magkos, F., Bier, D. M., Brenna, J. T., de Oliveira Otto, M. C., Hill, J. O., … & Krauss, R. M. (2020). Saturated fats and health: a reassessment and proposal for food-based recommendations: JACC state-of-the-art review. Journal of the American College of Cardiology, 76(7), 844-857.

This is a useful but not an isolated study. Links to other evidence in our Science Sources section below suggest similar results. Healthy foods that deserve many stars are often those least processed and closer to the foods that humans have always eaten. 

The overall recommendation of this review is that:

“The long-standing bias against foods rich in saturated fats should be replaced with a view toward recommending diets consisting of healthy foods.”

A similar evidence review that includes eight meta-analyses focussed on the health effects of dairy foods found no beneficial effects of reducing saturated fat intake on cardiovascular disease and total mortality, and instead found protective effects against stroke. The overall conclusion:

“…the current evidence supports the view that the full-fat dairy foods milk, yogurt, and cheese are nutrient rich and may be consumed without producing adverse effects on the cardiometabolic risk marker profile.”

Hirahatake, K. M., Astrup, A., Hill, J. O., Slavin, J. L., Allison, D. B., & Maki, K. C. (2020). Potential cardiometabolic health benefits of full-fat dairy: the evidence base. Advances in Nutrition, 11(3), 533-547.

This review found that their meta-analyses of both observational studies and RCTs did not suggest any harmful effects of full-fat dairy consumption on cardiometabolic disease and that much of the evidence used to inform dietary guidelines is of poor quality.

This is a problem.

If the food star ratings are supposed to help consumers with a simple visual way of choosing healthy food products, it is critical that the calculations used to decide on how many stars use the best available evidence. Otherwise, we are getting false information.

Reliability and accuracy are problems common to all indicators. They abstract a complex truth and should only be a guide. But a guide tells us where to go and, like sheep, we go there because we don’t have the time or the skills to complete evidence reviews ourselves.

bowl of dim sims that should get a high food star rating

Photo by charlesdeluvio on Unsplash


What sFED suggests

At best, the current food star rating in Australia is misleading. It omits important evidence and appears to follow an old paradigm for what constitutes healthy food. We have to say that this problem is not unique to Australia; it’s everywhere.

At worst the food star rating appears to be more about selling products than informing consumers on their dietary health.

We get it. Modern human societies are underpinned by commerce, where all sorts of goods and services are bought and sold. Players in markets play. They want to make sales and will look for every advantage to cajole customers. 

But food should be a special category of product. Like cigarettes or anything else that ends up in our bodies, there is a risk of harm if we consume the wrong food. There should be health warnings as well as health ratings.

We also know that harm is easier to measure and warn against than health is to promote. What an elite athlete consumes is not like a diagnosed diabetic or the average Joe picking up his blueberry muffin to go with his second coffee of the working day. What is an improvement over the muffin and healthy for Joe might ruin the athlete’s chance of winning. Health is very personal.

The Australian Dietary Guidelines are currently under review, with a revised version due in 2024. We await that revision with great interest. It is an opportunity to update the evidence and not make the mistake the US made recently when they updated their guidelines and changed little.  

We indeed are what we eat. 

If I could ask my liver if it feels healthy after a night on the town ends with a greasy kebab to soak up the alcohol, it would laugh at me in an ironic cackle. Then when I go to the store and make purchases based on a food star rating, it would roll about on the floor. 

The bureaucrat tasked with designing the food star rating scheme will quickly remind me that he must not only contend with this dissonance in the buying public but the government must also balance food production and availability for all its citizens. This makes the food star rating part of the food system and even the global six-continent food supply chain. It’s bigger than the individual.

And he has a point.

In this messy tale of food star rating, our key message here is one of caution. Food that makes us healthy is not as profitable as many foods currently on supermarket shelves.

That’s a conundrum that market forces will not fix.


Science sources

Intake of saturated and trans unsaturated fatty acids and risk of all cause mortality, cardiovascular disease, and type 2 diabetes: Systematic review and meta-analysis of observational studies 

Impact of whole dairy matrix on musculoskeletal health and aging–current knowledge and research gaps.

Dairy Fats and Cardiovascular Disease: Do We Really Need to Be Concerned? 
Dairy Consumption and Cardiometabolic Diseases: Systematic Review and Updated Meta-Analyses of Prospective Cohort Studies.


Hero image modified from photo by Martijn Baudoin on Unsplash

Chris

Chris is a latecomer to ecology but has happily landed where he should have been all along as an ecological practitioner in his bush regeneration business. When not out passionately managing land, trawling the evidence on nutrition, diet and health or carefully advising NGOs and government, he grows plants in his commercial nursery

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