Undernutrition in children under five associated with wealth-related inequality in 24 low-and middle-income countries from 2017 to 2022

Undernourishment is a persistent public health problem contributing to increased mortality in children under five in low-income countries, likely exacerbated by socio-economic disparities within communities. This paper aimed to examine the effect of wealth-related inequality on undernutrition in children under five in low, lower-middle, and upper-middle-income countries (LMICs). We analyzed cross-sectional data from the demographic and health survey program collected between 2017 and 2022 from 24 LMICs. Children born within 5 years preceding the survey were included in the analysis. Child undernutrition was the dependent variable (measured by stunting, wasting, and underweight) and country-level wealth-based inequality was the independent variable assessed by concentration index values stratified by the World Bank’s income categories. Within country inequality of child undernutrition was determined by concentration index (C) values with 95% confidence intervals (95% CI) and sub-group analysis by place of residence and sex of the child. We then fit bootstrapped meta-regression to check the variation in inequality of child undernutrition across different income category countries. The analysis was controlled by potential confounding variables. From the total sample size of 334,502 children included in the study, 35% were undernourished. Wealth-related inequality in child undernutrition was observed in 11 countries, consistently across income categories. Child undernutrition was highly concentrated among the poor households of Türkiye [C: − 0.26, 95% CI − 0.31 to − 0.20], and Cameroon [C: − 0.19, 95% CI − 0.22 to − 0.17], and relatively it was less concentrated among the poor in Liberia [C: − 0.07, 95% CI − 0.11 to − 0.04], and Gambia [C: − 0.07, 95% CI − 0.11 to − 0.04]. There is no difference in undernutrition associated with inequality between the three broad LMIC categories. The wealth-related inequality in child undernutrition within many of the included countries is still very significant. However, the economic category of countries made no difference in explaining wealth-related inequality in child undernutrition. Inter-sectoral collaboration to fight poverty and render special attention to the disadvantaged population segments would potentially help to address the observed inequity.