Regular participation in moderate-to-vigorous physical activity has been associated with adaptive physical and psychological health benefits including lower risk of non-communicable disease and reduced incidence of mental health conditions. However, a substantive majority the global population does not participate in sufficient physical activity to confer these health benefits, and inactivity levels are particularly high in underrepresented and disadvantaged minority groups, as indicated by negative associations between physical activity participation and socio-structural variables (e.g., socioeconomic status, income, education, health literacy). In addition, evidence suggests that participation in health behaviors such as physical activity partially mediates the association between these sociodemographic variables and health outcomes. We propose a process model specifying a candidate mechanism that may explain the association between socio-structural variables that represent disparity and health behaviors such as physical activity. Specifically, we propose a model in which beliefs such as attitudes, subjective norms, risk perceptions, and self-efficacy mediate associations between socio-structural variables and physical activity participation. After proposing the basic tenets of the model, we provide several examples illustrating the proposed effects for socio-structural variables including socioeconomic status and income, education, and health literacy in Asian contexts, and outline how these effects should be interpreted. We conclude by outlining the theoretical and practical relevance of these findings, and how they may inform interventions aimed at having adaptive effects on health outcomes by promoting physical activity participation and assisting in reducing health behavior disparities in Asian populations.