Defining 'Unhealthy': A Systematic Analysis of Alignment between the Australian Dietary Guidelines and the Health Star Rating System

The Australian Dietary Guidelines (ADGs) and Health Star Rating (HSR) front-of-pack labelling system are two national interventions to promote healthier diets. Our aim was to assess the degree of alignment between the two policies. Methods: Nutrition information was extracted for 65,660 packaged foods available in The George Institute's Australian FoodSwitch database. Products were classified 'core' or 'discretionary' based on the ADGs, and a HSR generated irrespective of whether currently displayed on pack. Apparent outliers were identified as those products classified 'core' that received HSR <= 2.0; and those classified 'discretionary' that received HSR >= 3.5. Nutrient cut-offs were applied to determine whether apparent outliers were 'high in' salt, total sugar or saturated fat, and outlier status thereby attributed to a failure of the ADGs or HSR algorithm. Results: 47,116 products (23,460 core; 23,656 discretionary) were included. Median (Q1, Q3) HSRs were 4.0 (3.0 to 4.5) for core and 2.0 (1.0 to 3.0) for discretionary products. Overall alignment was good: 86.6% of products received a HSR aligned with their ADG classification. Among 6324 products identified as apparent outliers, 5246 (83.0%) were ultimately determined to be ADG failures, largely caused by challenges in defining foods as 'core' or 'discretionary'. In total, 1078 (17.0%) were determined to be true failures of the HSR algorithm. Conclusion: The scope of genuine misalignment between the ADGs and HSR algorithm is very small. We provide evidence-informed recommendations for strengthening both policies to more effectively guide Australians towards healthier choices.