Child health across the rural–urban spectrum

•In East Africa, child stunting reduces rapidly at low levels of urbanization.•At the highest levels of urbanization stunting improvements level off or worsen.•Increased stunting in cities is driven by children from the 50% richest households.•Healthcare access and sanitation contribute to improvements in child stunting.•Worsening feeding practices possibly lead to higher stunting in bright city regions. It is widely known that in sub-Saharan Africa child health outcomes are better in urban than in rural areas. Less is known about how they evolve across different levels of urbanization. We use nighttime light intensity as a continuous measure of urbanization and reveal large differences both between and within urban agglomerations. We then link stunting levels recorded in recent Demographic and Health Surveys (DHS) for 40,000 children from ten East African countries, to local nighttime light intensity to document how child health evolves across the urban spectrum. In all ten countries child stunting improves rapidly at low levels of urbanization. At the highest levels of urbanization two different trends can be discerned. For one group of countries the improvements level off, for the other group they deteriorate. The deterioration is especially notable for children from the two richest wealth quartiles. Investigating probable proximate causes of these patterns we track how a number of determinants of child health vary with urbanization. We find that healthcare access and sanitation improve with urbanization and so likely contribute to the initial improvements in child stunting. Child feeding practices, such as meal frequency, consumption of iron-rich foods and diet diversity, also improve initially but deteriorate at the highest levels of urbanization, possibly explaining why child health outcomes do not continue to improve or even worsen in the most economically active urban areas.