Food for Rome: A stable isotope investigation of diet in the Imperial period (1st–3rd centuries AD)

During the Empire, the population of Rome was composed mostly of lower-class free citizens and slaves. Viewed from historical records, the Roman diet included primarily olives, wine, and wheat, but poor and enslaved Romans may have eaten whatever they were able to find and afford, leading to significant heterogeneity in the Roman diet. Previous carbon and nitrogen isotope analyses of skeletons from Imperial Italy have begun to reveal variation in diet, but little is known about what people ate in the capital city. This study complements previous work by adding new isotope data from human skeletons found in two Imperial-period (1st–3rd centuries AD) cemeteries in Rome. These data suggest that urban and suburban diets differed, most notably in the consumption of the C4 grain millet. Comparing these new data with all published palaeodietary data from Imperial Italy demonstrates that significant variation existed in the diet of the common people.

► We performed C and N isotope analyses on 48 individuals from Imperial Rome.
► Most people consumed a diet composed of C3 plants and aquatic protein.
► One adult had a predominantly C4 diet, and one child had not been fully weaned.
► People living in the suburbs ate more C4 resources than people living near the city.
► Comparison with other data from Imperial Italy suggests heterogeneity in the diet.