Understanding the barriers to purchasing healthier, more environmentally sustainable food for people living with obesity and varying experiences of food insecurity in the UK

•In people living with obesity:•Greater experiences of food insecurity are associated with lower diet quality via mental ill-health.•Greater experiences of food insecurity are associated with lower diet quality via food insecurity stigma.•Grocery store interventions based on price/incentivisation ranked most helpful.•Grocery store interventions based on awareness/education ranked least helpful. In westernised countries, food insecurity (FI) is robustly associated with low diet quality, and obesity. Grocery stores are one promising arena for interventions to facilitate purchasing of healthier, more environmentally sustainable food. However, we currently lack understanding of the barriers experienced by people living with obesity (PLWO) and FI when shopping for such food. Using an online survey (N = 583), adults residing in England or Scotland with a body mass index of ≥ 30 kg/m2 self-reported on FI, diet quality, and their experiences of shopping in a grocery store for healthy and environmentally sustainable food. Participants also ranked different grocery store interventions on their helpfulness in supporting healthier, more environmentally sustainable purchasing. Structural equation modelling revealed that greater experiences of FI were directly associated with greater experiences of barriers from the food environment (e.g., price), food preparation practices, lower healthy diet knowledge and physical ill-health. Moreover, greater experiences of FI were indirectly associated with lower diet quality via mental ill-health and greater experiences of anticipated stigma associated with being food insecure. Grocery store interventions based on price/ incentivisation were ranked most helpful in supporting healthier, more environmentally sustainable purchasing. These findings highlight the challenges faced by PLWO and with greater experiences of FI when shopping for healthy and environmentally sustainable food. Findings also underscore the need for policy development relating to price and affordability at a population-level, and for policymakers and healthcare professionals to consider how to address mental health and how to minimise anticipated stigma experienced by this vulnerable group.