Dietary Variation in an Urbanizing City: A Temporal Analysis of Diet in Late Medieval London Using Stable Isotope Analysis

Abstract

The process of urbanization is often characterized by high levels of migration, elevated food insecurity, and risks of disease epidemics. Stable isotope analysis of human skeletal remains can be used to identify dietary trends associated with urbanization that may not be evident using osteological analyses alone. δ13C and δ15N stable isotope values from individuals from a late medieval London cemetery (ca. 1120–1539 CE) are evaluated to assess how diet changed through time in an urbanizing environment with increasing population density and periods of famine, including separate analyses for age groups and the sexes. Analyses reveal stable isotope values varied both through time and by age group, but not by sex. Post-hoc regression analysis indicates that δ13C and δ15N values increase steadily from ca. 1120 to 1400 CE, which could reflect a decrease in the variation of food sources as a result of changing import strategies or famine conditions prior to the Black Death. Post-hoc pairwise comparisons show adults exhibit elevated δ15N values compared to nonadults, which may be a result of physiological changes affecting stable isotope values of growing individuals, migration, or differential access to certain protein sources. Analyses between and within the sexes indicate a lack of difference between the sexes through time, contrary to previous studies of less-urbanized English towns that have found a significant difference in stable isotope values between the sexes.