An ecological study of the association between childhood stunting, water, sanitation, and protein access, 2001-20

Abstract

Background Adequate height attainment during early childhood foreshadows lifelong health. Stunting may be caused by environmental enteropathy (EE), but EE has persisted after improvements in water and sanitation access. Recent studies suggest tryptophan and other amino improve height attainment. Methods This study used ecological data from 94 countries over 21 years (2001-20) (n = 1836) to evaluate the association between stunting and environmental variables: the percentage with access to adequate water and sanitation, country-level supply of animal protein and fish protein access, and per capita real gross domestic product. We used mixed effects linear models with varying intercepts by country after verifying residuals were uncorrelated and had uniform variance. Results Water/sanitation access and animal protein supply are associated with lower stunting: each 1 standard deviation change in water/sanitation was associated with 1 lower standard deviation of stunting, and each 1 standard deviation change in animal protein supply was associated with 0.2 lower standard deviations of stunting. Controlling for year, each 1 standard deviation change in water/sanitation was associated with 0.8 lower standard deviation of stunting, and each 1 standard deviation change in animal protein supply was associated with 0.1 lower standard deviations of stunting. Conclusions Improvements in water/sanitation infrastructure and animal protein access are both important interventions to reduce childhood stunting. These findings complement the 2023 FAO report conclusions regarding the importance of land animal protein to childhood growth.