Variables from modern epidemiological models can be used to reconstruct infant-mortality rates, childhood-growth patterns, and the onset of fertility in the Roman Empire from osteoarchaeological evidence. The anthropometry of Roman sub-adult skeletons compares closely to that of the unhealthiest modern and premodern populations, thus supporting pessimistic estimations of life expectancy at birth for Roman populations. Furthermore, the onset of female fertility was delayed due to childhood morbidity and malnutrition.