The sustainability of food systems is recognized as important, but to move towards sustainability individuals must play a larger role, becoming responsible food consumers. Based on diverse literatures and observed practices, the multidisciplinary Ekomer research team conceptualized responsible food consumption and designed a Responsible Consumption Index (RCI). The RCI was applied in a sample of randomly selected households in three city regions, or counties of Ecuador (Ibarra, Quito, and Riobamba) and in samples of individuals shopping at agroecological food outlets or fairs (open air markets). We describe the heterogeneous distribution of our RCI’s dimensions, the overall score across different populations and present some preliminary analyses of its positive relationship with daily fruit and vegetable consumption as well as table salt reduction practices. We reflect on the meaning of our findings and their implications for strengthening more sustainable and healthier food regimes in city regions.