Consumer food purchasing and willingness to adopt a sustainable healthy diet (SHD) is a key factor affecting the sustainability of the entire food system. Studies have developed scales to measure consumer preferences for particular consumption patterns, while others have sought to empirically define the multiple dimensions of a sustainable food system (environmental, social, economic, etc.). This paper builds on these literatures by tracking consumers' SHD behaviors using a large-scale, longitudinal survey of adults in the United States and mapping them onto multiple systems-level indicators. We wanted to know whether consumers interact with the sustainability of their food along the same principles developed by experts. Our study defines 18 food purchasing behaviors that support the sustainability goals of leading scientific institutions, uses factor analysis to identify the unobserved drivers behind these behaviors, and creates SHD scores to investigate their correlations with other consumer characteristics and behaviors. Factor analysis results show consumer food purchasing is motivated by three underlying sustainability dimensions-Economic Security, Socio-Environment, and Nutrition-which are fewer constructs than often defined by academic researchers. SHD scores reveal higher adoption of behaviors that fall under Economic Security relative to the other two dimensions. All three sustainability constructs are impacted by socio-economic and demographic characteristics. All rights reserved, Elsevier.