Isotopic reconstruction of human diet at the Roman site (1st-4th c. AD) of Carrer Ample 1, Barcelona, Spain

To investigate dietary patterns, collagen stable isotope ratios (δ13C and δ15N) were measured from fauna (n = 21) and humans (n = 23) from a rescue excavation at the Roman site (1st to 4th c. AD) of Carrer Ample 1 in Barcelona, Spain. The adult human results (δ13C = − 18.9 ± 0.3‰; δ15N = 11.1 ± 0.4‰) indicate a C3 terrestrial diet based on domestic animals such as pigs and sheep/goats, with no differences between the males (δ13C = − 18.8 ± 0.4‰; δ15N = 11.0 ± 0.4‰) and females (δ13C = − 19.0 ± 0.2‰; δ15N = 11.1 ± 0.5‰). Two infants show 15N-enriched (14.2‰ and 16.1‰) results characteristic of nursing, and a child of 4–5 years of age (δ15N = 13.0‰) suggests that breastfeeding could have continued until at least this age for some individuals. The two older children (8–10 years old) showed the most 15N-depleted values (8.9‰ and 9.1‰), and this is possible evidence of an adolescent diet that was different compared to the adult population. Comparison of the Carrer Ample 1 results with previous isotopic research from other coastal Roman sites (Leptiminus, Isola Sacra, Velia, Poundbury) shows that a degree of regional variability in diet existed within the Roman Empire.