# The Author(s) 2015. This article is published with open access at Springerlink.com Abstract Systems modeling represents an innovative ap-proach for addressing the obesity epidemic at the community level. We developed an agent-based model of the Baltimore City food environment that permits us to assess the relative impact of different programs and policies, alone and in combination, and potential unexpected consequences. Based on this experience, and a review of literature, we have identified a set of principles, potential benefits, and challenges. Some of the key principles include the impor-tance of early and multilevel engagement with the com-munity prior to initiating model development and contin-ued engagement and testing with community stakeholders. Important benefits include improving community stake-holder understanding of the system, testing of interven-tions before implementation, and identification of unex-pected consequences. Challenges in these models include deciding on the most important, yet parsimonious factors to consider, how to model food source and food selection behavior in a realistic yet transferable manner, and identi-fying the appropriate outcomes and limitations of the model