Infant Feeding Patterns and Sex-Differentiated Weaning in a Medieval Ligurian Village of Noli (9th–12th centuries ce): Evidence From Incremental Dentine Microsampling

Abstract

This study investigates exclusive breastfeeding, weaning age, and complementary diet among medieval juveniles interred in the San Paragorio church cemetery in Noli, Italy (9th–12th centuries ad). Incremental dentine microsampling (IDM) was applied to reconstruct high-resolution carbon (δ¹³C), nitrogen (δ¹⁵N), and sulfur (δ³⁴S) isotope profiles from birth through approximately 10 years of age using both deciduous and permanent molars from 23 genetically sexed juveniles. Comparative baseline data (δ¹³C, δ¹⁵N, and δ³⁴S) were generated from bone collagen of local faunal specimens. Age-at-death estimates were refined using micro-CT analysis. Isotopic trajectories reveal a marked sex difference in weaning patterns: Males exhibited slightly longer exclusive breastfeeding durations and substantially later weaning completion than females. These findings provide the first direct evidence of sex-differentiated weaning in medieval Liguria, contributing new insights into diet, parental investment, and childcare in a coastal community of the Middle Ages.