“It was a force for good but…”: a mixed-methods evaluation of the implementation of the high in fat, sugar and salt (HFSS) legislation in England

• Stakeholders viewed the legislation as a force for good but highlighted challenges in implementation and enforcement. • Stakeholders reported limited government communication, delayed guidance, and access to product nutrition data as key implementation challenges. • Seven policy recommendations were co-developed to support the development and implementation of effective food policy in future. In 2022, legislation in England restricted products high in fat, sugar, or salt (HFSS) in prominent store locations. This study explores retail sector (including enforcement of legislation in retail) responses to the legislation’s implementation. Four major UK retailers – ASDA, Morrisons, Sainsbury’s and Tesco − completed business-level online surveys. Interviews were conducted with representatives from three retailers (n = 13; Asda, Morrisons, Sainsbury’s), the British Retail Consortium (n = 1), and primary authority enforcement (n = 1) (N = 15). Data were collected between July and November 2024. Findings informed co-production workshops (n = 3) to develop policy recommendations. Stakeholders supported legislation aims but voiced concerns about complexities with interpretation and implementation, limited communication with government, access to product nutrition data, and delays to guidance. Retailers utilised various HFSS product promotional strategies while achieving compliance. Retailers reported very limited enforcement. These findings were synthesised and facilitated the development of seven policy recommendations through co-production workshops between academics and the Institute of Grocery distribution. HFSS legislation represents a landmark shift in regulation of the retail food environment, but clearer, timely guidance, data provision, and transparent co-production with actors cognisant of the food sector is needed to ensure legislation can be effectively implemented, enforced and evaluated.