Comment: 8 pages, 1 figureWhen it comes to preventive healthcare, place matters. It is increasingly clear that social factors, particularly reliable access to healthy food, are as determinant to health and health equity as medical care. However, food access studies often only present one-dimensional measurements of access. We hypothesize that food access is a multidimensional concept and evaluated Penchansky and Thomas's 1981 definition of access. In our approach, we identify ten variables contributing to food access in the City of Chicago and use principal component analysis to identify vulnerable populations with low access. Our results indicate that within the urban environment of the case study site, affordability is the most important factor in low food accessibility, followed by urban youth, reduced mobility, and higher immigrant population.