Cross-border food reformulation: changes in nutrient content in Uruguay following the implementation of front-of-package policies in neighbouring countries

BACKGROUND: Food reformulation is frequently discussed as a potential strategy to address obesity and diet-related non-communicable diseases. However, evidence regarding its effectiveness and broader implications within globalised food systems remains limited. This study examined changes in the nutrient content of packaged foods commercialised in Uruguay between 2021 and 2025, a period characterised by limited domestic regulatory action but during which front-of-package (FOP) warning label policies were implemented in Argentina and Brazil, Uruguay's main trading partners. METHODS: Nutrient information was obtained through systematic in-store data collection and compiled into an online database. Linear mixed-effects models were used to estimate changes in nutrient content, accounting for repeated product-level observations and testing interactions between year and country of origin. RESULTS: At the aggregate level, modest but statistically significant reductions were observed in total fat, saturated fat, and sodium, alongside a small increase in fibre content. However, significant interactions between year and country of origin revealed substantial heterogeneity in reformulation patterns. Products imported from Argentina showed the most pronounced reformulation, with significant reductions in total fat, saturated fat, and sodium, and increases in fibre content. In contrast, domestically produced products in Uruguay exhibited limited reformulation, with statistically significant changes observed only for saturated fat and of smaller magnitude. Products from Brazil and other countries showed minimal changes, with statistically significant increases limited to fibre content. Category-level analyses further indicated that reformulation effects were uneven across the packaged food supply. CONCLUSIONS: These findings are consistent with the possibility that the implementation of FOP warning labels in Argentina was associated with reformulation with spillover effects into the Uruguayan market. Differences in policy design, particularly the stringency of the underlying nutrient profile model, may help explain the divergent industry responses. The limited changes observed among domestic products in the period highlight the need for complementary policy instruments to promote more substantial reformulation.