Aztec diets at the residential site of San Cristobal Ecatepec through stable carbon and nitrogen isotope analysis of bone collagen

This paper presents the first systematic study of Aztec diets using bone collagen stable carbon and nitrogen isotope analysis. The objective was to identify the dietary patterns of an Aztec community living in the Basin of Mexico. The collection analyzed includes adult and subadult skeletons from the residential site of San Cristóbal Ecatepec (in present-day Mexico State) (A.D. 900–1521). The isotopic data were compared with available ethnohistoric and archeological information about Aztec diets. We conclude that Ecatepec residents consumed mostly C4 and CAM plants (as opposed to C3 plants), terrestrial animals, and some lacustrine resources. They shared similar diets and foodways, as indicated by the fact that they belonged to the same socio-economic group and that there were no substantial sex-based differences indicated by the isotopic data. The slightly higher carbon isotope compositions of the men compared with the women could be evidence of pulque consumption by the men—as noted in the ethnohistoric record. The nitrogen isotope compositions of the subadults, however, show some variability related to breastfeeding and weaning practices, with infants weaning between 2 and 4 years of age.