Socio-economic status and overweight or obesity among school-age children in sub-Saharan Africa - a systematic review

Childhood overweight and obesity have emerged as a public health concern in sub-Saharan Africa. We conducted a systematic review with the aim to examine the association between socio-economic status (SES) and overweight or obesity among school-age children in sub-Saharan Africa. In March 2014 we searched five electronic databases for reports which presented cross-sectional data on prevalence levels of overweight or obesity stratified by SES groups among school-age children in sub-Saharan Africa. We used a random-effect model to pool the relative indexes of inequality of the association from the individual studies. In total, 20 reports satisfied the inclusion criteria providing results of 21 datasets. The risk of overweight or obesity in children from highest SES households was 5.28 times as high as that of children from lowest SES households (95% confidence interval [CI] 2.62 to 10.66). On subgroup analysis, this association was statistically significant for household income and composite SES measures but not for parental educational attainment and occupation type. Similarly, the risk of overweight or obesity in children attending affluent (private) schools was 15.94 times as high as that of children going to either urban or rural public schools (95% CI 5.82 to 43.68). The magnitude of the association tended to be stronger for area or school-type compared with composite measures. In summary, children from higher SES households and those attending private schools tended to be overweight and obese.