Widespread reduction in traditional foods has been extensively documented around the world, despite a growing scholarship in ethnobiology and nutrition studies attesting to the value and importance of traditional food systems. A processual ethnobiology approach—one attuned to the historically situated nature of traditional ecological knowledge, and the influence and interplay of micro- and macro-level forces—may offer new insights into processes of dietary change and continuity. Using this perspective, I present a case study from Southern Bolivia on rural peoples' descriptions of how and why their foodways have changed over time, as well as how their traditional food system is being sustained. I draw on data gathered over 12 months through interviews, participation, participant observation, and document review. Animal protein and commercial crop production promotion and discourses disparaging traditional meals are some of the factors affecting availability, affordability, and acceptability of traditional foods. Nevertheless, there are also many examples of how local foods and recipes have been adapted, rather than abandoned, and of promising initiatives rebuilding the prestige and cultural acceptability of traditional foods. These findings suggest a more complex and nuanced process of dietary change than is often posited in the nutrition transition model. Place-specific, historically informed understandings of how attitudes, availability, and other factors have influenced local food systems are needed to develop policies and programs that effectively respond to locally identified concerns surrounding the continuity of traditional food use.