This study presents the largest regional-scale stable isotope investigation of human and faunal remains spanning the Bronze and Iron Ages (c. 2400–100 BCE) in the Eastern Adriatic to date. New δ13C and δ15N data from 51 individuals were integrated with previously published results (n = 233) to explore long-term and region-specific dietary trends, with a focus on the emergence of millet as a dietary component. Results reveal an inland–coastal contrast: while coastal populations predominantly consumed C3-based diets, inland groups show consistently higher δ13C values indicative of direct millet intake from the Middle/Late Bronze Age onwards. Statistical analyses confirm strong effects of both period and location on δ13C values, with most inland populations exhibiting more positive signatures particularly during the Middle/Late Bronze Age transition and again in the Iron Age. A probabilistic two-endmember mixing model estimates millet contributions reaching up to ~ 40% of dietary protein in these inland groups, suggesting episodic but significant integration of C4 crops into subsistence systems. In contrast, faunal baselines reflect purely C3 diets, indicating that the C4 signal in humans derives from direct millet consumption. These findings help refine the chronology of millet adoption in the eastern Adriatic, pushing its significant dietary incorporation back to the Middle/Late Bronze Age transition, and highlight fluctuating patterns of C4 plant consumption through the Bronze and Iron Ages, likely shaped by ecological conditions and local adaptive strategies rather than uniform cultural change.
Martinoia et al. (Wed,) studied this question.