Food has long served as a mechanism for identifying and reinforcing social structures, but while carbon and nitrogen isotope analysis has provided important identity-based evidence of past diets, the cyclical and stable/fluid nature of food consumption practices across the life course has been relatively neglected. In this paper, the large human assemblage at Çatalhöyük with all age groups present has enabled diet reconstruction of the rarely represented groups of older children and adolescents as well as for the young, middle and old adult age groups of both sexes. These data show how neonates reflect foods available to pregnant mothers, that infants were breastfed until around 18 months of age and weaned by three years of age, older children had a different diet compared to adolescents and young adults who, in turn, differed from middle and older adults. The absence of sex-related differences suggests changes in food consumed at Çatalhöyük accompanied the marking of transitions through the life course.