Residence-based inequalities in overweight/obesity in sub-Saharan Africa: a multivariate non-linear decomposition analysis

Background Overweight/obesity remains a major risk factor for non-communicable diseases and their associated morbidities and mortalities. Yet, limited studies have comprehensively examined factors contributing to the rural-urban disparities in overweight/obesity among women in sub-Saharan Africa. Thus, our study sought to decompose the rural-urban disparities in overweight/obesity among women in sub-Saharan Africa (SSA) using nationally representative datasets.Methods We performed a cross-sectional analysis of data from the Demographic and Health Surveys of 23 sub-Saharan African countries conducted from 2015 to 2022. A sample of 177,329 women was included in the analysis. Percentages with confidence intervals (CIs) were used to summarize the prevalence of overweight/obesity per rural-urban strata and pooled level. A multivariate non-linear decomposition analysis was used to identify the factors contributing to the rural-urban disparities in overweight/obesity. The results were presented using coefficients and percentages.Results The pooled prevalence of overweight/obesity among the women was higher in urban areas (38.9%; 95% CI = 38.2-39.6) than rural areas (19.1%; 95% CI = 18.7-19.6). This pattern was observed in all the countries surveyed, except in South Africa, where women in rural areas (53.1%; 95% CI = 50.0-56.4) had a higher prevalence of overweight/obesity than those in urban areas (46.0%; 95% CI = 43.2-48.9). Approximately 54% of the rural-urban disparities in overweight/obesity was attributable to the differences in the women's characteristics or explanatory variables. More than half of the rural-urban disparities in overweight/obesity would be reduced if the disparities in women's characteristics were levelled. Among the women's characteristics, frequency of watching television (29.03%), wealth index (26.59%), and level of education (9.40%) explained approximately 65% of the rural-urban differences in overweight/obesity.Conclusion The prevalence of overweight/obesity among women in SSA remains high and skewed towards women in urban areas. Increased frequency of watching television, high wealth index, and higher educational attainment contributed largely to the rural-urban disparities in overweight/obesity among women in SSA. Thus, interventions aimed at reducing overweight/obesity among women in SSA could be targeted at reducing the frequency of television watching as well as promoting physical activities among wealthy women and those with higher education, particularly in urban areas.