Cross-National Comparisons of Time Trends in Overweight Inequality by Socioeconomic Status Among Women Using Repeated Cross-Sectional Surveys From 37 Developing Countries, 1989–2007

TLDR

Chronic diseases are now leading causes of morbidity and mortality in low‑income countries, and the relationship between socioeconomic status and these diseases is shifting, with country‑level factors such as economic development and income inequality shaping how overweight prevalence changes over time. The study examined repeated cross‑sectional data from 405,550 women aged 18–49 in 37 developing countries to evaluate how overweight inequalities by socioeconomic status evolved between 1989 and 2007. Meta‑regression was employed to assess how gross domestic product and country‑level income inequality modified the rate of overweight prevalence increases across socioeconomic groups. In 27 of 37 countries higher SES was linked to larger gains in overweight prevalence, while in 10 countries lower SES showed greater gains, and higher GDP was associated with faster overweight increases among poorer groups, with lower income inequality in high‑GDP countries further accelerating overweight growth among the poor.

Abstract

Chronic diseases are now among the leading causes of morbidity and mortality in lower income countries. Although traditionally related to higher individual socioeconomic status (SES) in these contexts, the associations between SES and chronic disease may be actively changing. Furthermore, country-level contextual factors, such as economic development and income inequality, may influence the distribution of chronic disease by SES as well as how this distribution has changed over time. Using overweight status as a health indicator, the authors studied repeated cross-sectional data from women aged 18–49 years in 37 developing countries to assess within-country trends in overweight inequalities by SES between 1989 and 2007 (n = 405,550). Meta-regression was used to examine the associations between gross domestic product and disproportionate increases in overweight prevalence by SES, with additional testing for modification by country-level income inequality. In 27 of 37 countries, higher SES (vs. lower) was associated with higher gains in overweight prevalence; in the remaining 10 countries, lower SES (vs. higher) was associated with higher gains in overweight prevalence. Gross domestic product was positively related to faster increase in overweight prevalence among the lower wealth groups. Among countries with a higher gross domestic product, lower income inequality was associated with faster overweight growth among the poor.