POPCORN is the short name of a French research consortium dedicated to methodological developments in urban metabolism studies about food and agri-food systems. POPCORN has developed a novel approach to assessing urban food consumption in socio-metabolic studies. The literature of urban food metabolism studies is characterized by discrepancies in study scope and method to quantify urban food consumption (Goldstein et al., 2017). Studies either use statistics of per capita food demand at city, regional or national level scaled to the resident population, while ignoring tourist and/or commuter activities and their contribution to the total urban food consumption (Codoban & Kennedy, 2008). Or they use input-output balance using trade statistics for imported and exported food (Barles, 2009; Rosado et al., 2014). The benefit of these approaches lies in the overall good availability of the required data and their easy operation. Their inconvenience lies in the approximate nature of the resulting food flows by either misestimating them, in the case of a focus on residents, or by having food consumption entangled with other output flows related to food, such as food waste. However, quantitative studies about e.g. cities’ or metropolitan areas’ degree of self-sufficiency in food supply (Schreiber et al., 2021) or linearity versus circularity of nutrient flows (van der Wiel et al., 2019) require a detailed assessment of urban food consumption. To overcome this limitation, POPCORN uses the concept of the eating population to characterize and quantify the actual number of eaters of a city, including tourists and commuters, and its related food consumption. Drawing on the notion of the present population defined by French institutions and on previous work inspired by the literature about civil service and wastewater management systems (Esculier, 2018; Redlingshöfer, 2019; Tedesco et al., 2017), the eating population is built by eating equivalents. This is a means to integrate different types of population and their respective characteristics as they pertain to total urban food consumption over a study period. The operationalization of the concept as developed so far combines, at the scale of municipalities, multiple and different types of population data from the field of tourism, transport and mobility, and food intake data available from a national survey. POPCORN has developed a web-based computation tool to facilitate the process while ensuring quality. In 2021, we presented the aims and the operationalization of the eating population concept at the AScUS conference (Redlingshöfer & Petit, 2021). Our first empirical results showed that the eating population and its related food consumption are equal or lower than comparable results calculated with the resident population, for the cities and peri-urban areas covered so far in our research. In 2022, at the 14th ISIE SEM conference, we aim to present the computation tool and new results of more diverse urban or peri-urban areas. We assess the role of selected characteristics of cities (their embeddedness in metropolitan areas or commutersheds, tourist places etc.) for the eating population and the total urban food metabolism.