Objective: Child undernutrition is a persistent public health problem contributing for about half of under-five child death in low-income countries, and it is severe among the poorest communities. The extent of socio-economic-related inequity in undernutrition within and between countries of differing economic standing is still a question. This paper, therefore, aimed to examine the wealth-based inequity in nutritional status among 24 low, lower-middle and upper-middle income countries.

Method: The most recent demographic and health survey data of children under the age of five were included. Inequity in child undernutrition was measured by concentration index (C) values and concentration curves. We then fit bootstrapped Mata regression to check whether there is a variation in inequality of child undernutrition across different income category countries.

Result: The overall prevalence of child undernutrition was 35%. The figure was highest in India (47%), and Ethiopia (38.9%), while it was lowest in Turkey (8.5%). Wealth-related inequalities in child undernutrition were detected in about half of the countries, and in all three economic categories. Child undernutrition was highly concentrated among the poor households of Turkey [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]. Meta-regression analysis revealed that there is no difference in the inequality levels between the three economic categories of countries.

Conclusion: The socio-economic-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 socio-economic-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.