The study of infant feeding in past human populations is an important area of investigation, as patterns of breastfeeding and weaning have long‐term consequences on growth, health, and survivorship. Prior to using biochemical techniques, weaning was inferred through osteological indicators of stress. Since the 1990s, there has been an increase in the use of stable isotopes to investigate the timing of breastfeeding and weaning. The stable isotopes of nitrogen and carbon in bone collagen are commonly used to investigate these patterns; however, uncertainties over bone turnover rates and the time required to register dietary shifts, along with biases created by analyzing nonsurvivors, have raised questions about the validity of using isotope data from subadult bone. Recent methodological developments focus on serial sampling of teeth to overcome some of these biases by studying infant and young child feeding in individuals who survived to adulthood.