Causal Loop Diagrams of Food Systems, Diet, and Obesity: A Scoping Review of Methods, Contextual Factors, and Outcomes.

This scoping review characterizes the literature on qualitative systems methodologies that guide interest-holders in developing causal loop diagrams focused on food systems, diet, and obesity. Peer-reviewed research using interest-holder-driven causal loop diagrams to examine food environments, access, purchasing, diet, obesity, and related interventions/policies was included. A comprehensive search of six databases (ProQuest Central, Scopus, Web of Science, Ovid MEDLINE, Embase, and Emcare) yielded 40 eligible studies from a pool of 1370 unique records. We synthesize study characteristics, the intended uses of causal loop diagrams, methodological approaches, evaluation processes, and key findings. While all studies identified individual and behavioral drivers of obesity, studies based in the Global South more frequently featured structural factors such as racism, discrimination, crime, and incarceration. Papers focused on engaging minoritized populations similarly emphasized structural-level themes such as urban agriculture, gentrification, community investment, and capacity building. Our findings highlight the potential of causal loop diagrams to capture the interconnectedness and complexity of food systems, diet, and obesity, along with gaps in the geographical coverage of study efforts, as well as the representation of key populations in current conceptualizations of food systems. This review offers methodological insights for researchers and practitioners seeking to apply causal loop diagrams to understand and address complex public health issues related to food systems, diet, and obesity within their local contexts.