Childhood stunting and cognitive development: a meta-analysis.

Background: Childhood stunting is associated with delayed developmental trajectories. While the relationship between childhood stunting and cognitive development has been widely studied, the impact on children's development requires further examination. We aimed to synthesise existing research studies to clarify the relationships between childhood stunting and cognitive development and sub-domains of cognition. Additionally, we sought to examine potential moderating factors influencing the relationship between childhood stunting and cognitive development, and to explore interventions targeted at improving cognitive development for stunted children.

Methods: We systematically reviewed literature from 1990 to 2025 in 54 languages. We identified 12 191 studies, of which 35 studies met the inclusion criteria and were analysed. We employed random effect models to calculate pooled effect sizes and assessed heterogeneity using I² statistics. We evaluated publication bias through Egger's test.

Results: Our initial model revealed no effects of childhood stunting on overall cognitive development. However, more refined domain-specific analyses showed that childhood stunting was associated with poorer sub-domains, specifically intelligence, executive function, visuo-spatial, cognition, and socio-emotional development in specific geographic regions. Secondary models indicated that the effects of childhood stunting were more pronounced when moderating factors such as demographics, socioeconomic, parent-related and health-related factors were controlled for, demonstrating the critical role of the impact of developmental context. Finally, the exclusive focus on nutritional interventions limited our ability to explore the effects of other intervention types on cognitive development in children who were stunted.

Conclusions: Our findings highlight the need for further research to better understand these relationships and for the development of contextual interventions to draw robust conclusions and design targeted interventions. Future research should explore standardised culturally sensitive assessment tools, emphasising the necessity of accurate reporting, and the exploration of moderating effects across cognitive sub-domains.