Arctic Indigenous food systems are typified by diverse social interactions that maintain food security. Given the numerous challenges Arctic Indigenous communities face, it is important to understand diversity in these systems and how they are impacted by change. This study adopts a mixed methods approach that combines participatory methods with network analysis to assess the diversity of food-related interactions between different actor types in the mixed food system on St. Paul Island, Alaska. We conducted 36 interviews with local food system actors to identify current food security challenges and food-related interactions in the local food system. We used network analysis to investigate the diversity of interactions in the food system quantitatively. We simulated the effects of two key food security challenges (out-migration and knowledge loss) on food system diversity and explored interventions to increase diversity. Qualitative data from the same interviews were used to embed our results in the lived realities of the St. Paul Island community. Our approach reveals diverse interactions in the local food system, reflecting both subsistence and market-based elements of the St. Paul Island mixed economy. While both challenges threaten the system's diversity, out-migration presents a more immediate risk to food system diversity than knowledge loss. We advocate for targeting a combination of food system interventions at the community level to enhance food system diversity effectively. Our research contributes to understanding the importance of diversity for Arctic Indigenous food security and emphasizes the need to recognize the complex interactions between food system interventions and their implications for Arctic Indigenous communities.