Abstract The topography of the Andean Region results in short travelling distances among ecologically distinct production zones. As such, it is possible to infer relative changes in residence based on the spatial variability in the isotopic composition of food resources. Here, we determine long-term diet through carbon- and nitrogen-isotope analysis of bone collagen for twenty-nine individuals from Cahuachi, an important ceremonial centre in the Nasca Region. We also reconstruct the temporal sequence of change in dietary isotopic compositions along hair samples for seventeen individuals buried at Cahuachi and the neighbouring site of Huaca del Loro. The collagen isotopic data for individuals buried at Cahuachi indicate that the average diet was a mix of C3 and C4 plant foods with greater reliance on maize, and included the variable consumption of plant-derived protein and terrestrial animals. Sequential isotopic analyses of hair reveal distinctive patterns of dietary shifting that distinguish seasonally changing diets from access to multiple production zones. We argue that short-term dietary heterogeneity in this context can be interpreted to represent flexibility as a risk-minimising strategy through the interaction between food acquisition and participation in local mobility among the Nasca.