We present a methodological approach for constructing an agent-based model (ABM) to assess community food security and variation among livelihood trajectories, using rural Malawi as a case study. The approach integrates both quantitative and qualitative data to explore how interactions between households and the environment lead to the emergence of community food availability, access, utilisation and stability over time. Results suggest that livelihoods based upon either non-agricultural work or farming are most stable over time, but agricultural labourers, dependent upon the availability of casual work, demonstrate limited capacity to step-up livelihood activities. The scenario results suggest that population growth and increased rainfall variability are linked to significant declines in food utilisation and stability by 2050. Taking a systems approach may help to enhance the sustainability of livelihoods, target efforts and promote community food security. We discuss transferability of the methodological approach to other case studies and scenarios. © 2018, University of Surrey. All rights reserved. SD was supported by an EPSRC Doctoral Training Centre grant (EP/G03690X/1). MS provided the village-level data collected under an ESPA Early Career Fellowship Grant (FELL-2014-104) with support from the Ecosystem Services for Poverty Alleviation (ESPA) programme. The expert workshop was organized with the support of the ‘Attaining Sustainable Services from Ecosystems using Trade-off Scenarios’ project (ASSETS; http: //espa-assets.org/; NE-J002267-1), which is also funded with support from ESPA. The ESPA programme is funded by the Department for International Development (DFID), the Economic and Social Research Council (ESRC) and the Natural Environment Research Council (NERC). SB was supported by two grants: BizkaiaTalent, Marie Curie Actions (People, Grant agreement n. 267230) and Juan de la Cierva incorporación (Grant IJCI-2014-22590).