Simulated retail food environments: A literature review of systems science approaches to advance equity in access to healthy diets.

As researchers increasingly utilize systems science simulation modeling (SSSM), little is known about how and by whom SSSMs are being leveraged to address inequities in access to healthy diets. We evaluated the extent to which studies (n = 66) employing SSSM to examine retail food environments (RFEs): included three pillars of equity (social position, human capital, socioeconomic and political context) that shape RFEs and access to healthy diets; grounded model design and development in theory; engaged with diverse stakeholders and lived experiences related to RFEs; and translated model findings towards addressing inequities in RFEs. Most studies (n = 58) included some model characteristics related to social position (e.g., age). Characteristics related to human capital (e.g., meal planning skills) were the least integrated fundamental pillar (n = 15). All studies included some characteristics related to socioeconomic and political context; however, we found little to no incorporation of social contexts (e.g., cultural and societal norms). Regarding model design and development, less than one-third of studies specified theoretical frameworks or engaged with local domain experts and stakeholders. While certain research objectives and, consequently, model types lend themselves better than others to address key pillars that influence RFEs, findings show that models are not fully leveraging SSSMs to analyze the multiple, interacting dimensions - particularly social phenomena - influencing equity in access to healthy diets. Greater attention to engaging stakeholders and the role of human capital and social contexts will likely better equip models to more holistically examine equitable food access, including essential pathways and unintended consequences of programs and policies.