PROTOCOL: Insights into processed food awareness and influences on their purchasing in People Living with Obesity and Food Insecurity v1

**Introduction: There is growing evidence linking processed food consumption to adverse health outcomes, including obesity and associated cardiometabolic diseases and mental health and well-being. Understanding consumer awareness of food processing and its impact on food purchasing behaviours is crucial for informing public health policies and guidance. This study employs a comprehensive survey to assess three primary research objectives: (1) examining consumer understanding of processed food, (2) understanding processed food purchasing patterns in people living with obesity and food insecurity, and (3) identifying determinants of processed food purchasing behaviour. Methods and analysis: An online survey administered via the Prolific platform will be used for data collection. The survey (approximately 25 minutes) incorporates validated food security assessment tools and consumer behaviour research methodologies to provide insights into the complex relationships between food security status, health conditions, and processed food consumption patterns in the UK context. Study inclusion criteria include participants aged 18–64 years, residing in England or Scotland. A target of 600 participants will be set. A mixed-methods analysis will be used to present the findings. Statistical analyses will seek to adjust for selection and participation bias. Qualitative analyses will draw on thematic analysis. Ethics and dissemination: Ethical approval will be obtained from Leeds Beckett University, UK. Anonymised study findings will be disseminated through scientific journals, conferences, institute websites and social media, and briefings tailored to policy, practice and the public, with the intention to inform future policy development for the food retail environment.