Gaming the Stars: Health Stars, Ultra-Processed Foods and What Neither System Sees
Let’s play a game.Food one is a raspberry cheesecake protein bar. Its ingredients include protein isolates, white chocolate sweetened with maltitol, polydextrose, glycerol, sorbitol, flavours, colour and emulsifiers, and there are more than twenty of them.Food two is a packet of shredded cheddar: milk, salt, culture, rennet and a little cellulose to stop the shreds sticking together.Which gets more Health Stars?Neither. They get four and a half stars each. And under the ultra-processed food classification, both count as ultra-processed. The cheese gets there because of that one anti-caking agent.These examples come from a peer-reviewed analysis of the Australian food supply. In this episode of Delicious Science, I use them to bring together two conversations that are now colliding in Australian food policy. FSANZ is working through a proposal to make the Health Star Rating mandatory. At the same time, ultra-processed foods have become one of the biggest topics in nutrition, and the NHMRC is reviewing the evidence on them as it updates our Dietary Guidelines.The problem is that the two ways of judging food often disagree, sometimes wildly.Delicious Science with Dr Joanna McMillan is a reader-supported publication. To receive new posts and support my work, consider becoming a free or paid subscriber.The star algorithm can be gamedHealth Stars work on a balancing act. A product gets risk points for energy, saturated fat, sugars and sodium, and then has points taken off for protein, fibre and fruit, vegetable, nut and legume content. That means a manufacturer can raise the rating by adding protein isolates, inulin or fruit powders, or by swapping sugar for a sweetener, without changing what the food really is.Research from Deakin University found that in the first five years of the system, 73% of ultra-processed foods carrying the label scored two and a half stars or more. So did more than half of discretionary foods, the biscuits, confectionery and snack bars our dietary guidelines say we only need sometimes.“Ultra-processed” isn’t the whole answer eitherNOVA, the ultra-processed classification, judges how a food is made, and it misses the nutrients. It flags a perfectly good fava bean snack because of a little maltodextrin in the seasoning. Meanwhile it waves through salty beef jerky and a sugary kombucha because they’re made with “kitchen” ingredients.I also want to push back on the idea that every additive is something to fear. Preservatives, nitrites and antioxidants such as vitamin C are often there for food safety. Fortifying bread with folic acid and iodine has been a genuine public health win. There are emerging questions about some emulsifiers and the gut microbiome, and I take them seriously. But my concern is less about any single additive and more about what the overall product is, and what it’s pushing off your plate.In this episode· How the Health Star algorithm works, and the four moves manufacturers use to win more stars· The voluntary loophole, and why we mostly see the good scores· What the latest trials tell us about ultra-processed diets, including the UK UPDATE trial· A round of “guess the stars” with real Australian products· A new Australian model that starts with processing and then checks sugar and salt· Chile’s warning labels, and the first evidence that they’ve affected children’s weight· Six practical tips for your next supermarket tripMy bottom lineThe Health Star Rating counts nutrients and NOVA judges processing. Both matter, and neither is enough on its own. If Australia is going to make front-of-pack labelling mandatory, and I think it should, so nobody can hide their low scores, let’s make sure we mandate a system that starts with the food and then checks the nutrients.In the meantime, you don’t need a perfect label to eat well. Eat mostly whole and minimally processed foods with lots of plants, use the processed foods that make life easier, and enjoy the occasional treat you really love.🎧 Listen to the full episode above.Your turn: have you spotted a product with surprising stars? Tell me in the comments. I’d love to do a listener round of “guess the stars”.Studies and referencesAustralian research (Dickie et al., Deakin University)· Dickie S, Woods JL, Baker P, Elizabeth L, Lawrence MA. How does the Australian Health Star Rating system perform after five years? Nutrients, 2020; 12: 1463.· Dickie S, Woods J, Machado P, Lawrence M. Nutrition classification schemes for informing nutrition policy in Australia. Current Developments in Nutrition, 2022; 6: nzac112.· Dickie S, Woods J, Machado P, Lawrence M. A novel food processing-based nutrition classification scheme applied to the Australian food supply. Frontiers in Nutrition, 2023; 10: 1071356.Front-of-pack labelling· Global Food Research Program, University of North Carolina. Front-of-Package Labeling Fact Sheet, January 2025.· Paraje G et al. The impact of Chile’s food labelling and advertising law on early childhood excess weight. The Lancet, 2026; 407: 2630–40.· Food Standards Australia New Zealand. Proposal P1067: Health Star Rating System.Ultra-processed food trials· Hall KD et al. Ultra-processed diets cause excess calorie intake and weight gain. Cell Metabolism, 2019.· Dicken SJ et al. Ultraprocessed or minimally processed diets following healthy dietary guidelines (UPDATE trial). Nature Medicine, 2025.· Monteiro CA et al. Ultra-processed foods and human health. The Lancet series, November 2025.Additives and the gut· Chassaing B et al. Randomized controlled-feeding study of dietary emulsifier carboxymethylcellulose. Gastroenterology, 2022.· Sellem L et al. Food additive emulsifiers and risk of cardiovascular disease in the NutriNet-Santé cohort. BMJ, 2023.· Food additive emulsifiers and the risk of type 2 diabetes (NutriNet-Santé cohort). The Lancet Diabetes & Endocrinology, 2024.Disclosure: I’m a non-executive director of Cobram Estate Olives, an Australian extra virgin olive oil company, and I’ve been involved in advocacy on how the Health Star Rating treats cooking oils.Delicious Science with Dr Joanna McMillan is a reader-supported publication. To receive new posts and support my work, consider becoming a free or paid subscriber. Get full access to Delicious Science with Dr Joanna McMillan at drjoannamcmillan.substack.com/subscribe
