Protein-enriched breakfast cereals receive similar Health Star Ratings despite higher sugar and sodium content

Front-of-pack nutrition labelling (FOPNL) on packaged foods can support consumers to make healthier choices. Australia and New Zealand's voluntary FOPNL, the Health Star Rating (HSR), summarises a product's healthiness from 0.5 (less healthy) to 5.0 (more healthy). Even though the population's protein requirements are largely met, protein content contributes positively to a product's rating, raising concerns that added protein may be used to offset unfavourable nutrients. Our aim was to compare breakfast cereals with and without added protein by examining the prevalence of HSR display, and differences in HSR and nutritional composition. Cross sectional study of breakfast cereals available for sale in Sydney, Australia, in 2024. HSRs were calculated using information available on pack. For products with and without added protein, we compared the proportion displaying an HSR on pack, and the median HSR, energy, sodium, total sugars, dietary fibre and protein (per 100g). Breakfast cereals with added protein (n = 49) had a higher prevalence of displaying the HSR compared to those without added protein (n = 436, 91.8 % v 76.1 %, p = 0.012). Both groups reported a median HSR of 4.0 (p = 0.266). Products with added protein contained significantly more sodium (120 [IQR 48-300] v 30 [IQR 10-174] mg/100 g, p < 0.001) and total sugars (15.6 [IQR 9.6-23.9] v 13.7 [IQR 8.1-18.5] g/100 g, p = 0.027). Food manufacturers benefit from adding protein to offset unfavourable nutrients and achieve relatively high HSRs. Consideration of the role and offsetting power of added protein is warranted to ensure that the HSR system, and similar systems used globally, guide consumers towards genuinely healthier products.