Marked dietary changes are occurring nationwide in Mexico, yet these manifest differently among distinct socioeconomic status (SES) groups. This article examines several complex relationships among: SES; food preferences, norms, and aspirations; and actual dietary practices in a Mexican city. Drawing on data from an in-depth ethnographic study conducted in Mazatlán, Sinaloa, this study takes a multidimensional qualitative approach in order to gain a more nuanced understanding of contemporary dietary changes and nutritional health disparities. Very few studies distinguish actual dietary behaviors from food preferences, interrogate disjunctures between dietary patterns and aspirations, or investigate tensions between normative and temptation food preferences. This work advances the literature by bringing together insights from Bourdieu's theory of habitus, (critical) consumer demand theory, and Popkin's theory of nutrition transitions to shed light on how SES not only shapes food consumption patterns but also the diets that people aspire to consume in a developing-country setting. The study finds that food practices and preferences are driven by economic constraints but also different kinds of socially structured exposures, access, beliefs, and norms.