Prevalence of Overweight and Obesity Among African Primary School Learners: A Systematic Review and Meta-Analysis

Abstract

Background: There is an increasing trend in the global prevalence of childhood overweight and obesity, presenting major public health challenge in developed and developing countries. We report the results of a systematic review and meta-analysis to estimate the prevalence of overweight and obesity among primary school learners residing in Africa according to different diagnostic criteria and population level characteristics. Methods: A comprehensive search of multiple databases was conducted to identify relevant research articles published between June 1980 and Feb 2017. Random effects models were used to pool prevalence data within and across population level characteristics, after variance stabilisation through arcsine transformation. Findings: Data from 45 studies across Africa comprising 92,379 and 89,468 participants for overweight and obesity estimates were included in the meta-analysis. Study quality was moderate. The overall overweight prevalence estimates by the major criteria were: 10.5% [95% CI: 7.1-14.3] by WHO, 9.5% [6.5-13.0] by IOTF and 11.5% [9.6-13.4] by CDC respectively and these differed significantly across criteria (p=0.0027). Obesity prevalence estimates for WHO, IOTF and CDC criteria were 6.1% [3.4-9.7], 4.0% [2.5-5.9] and 6.9% [5.0-9.0] with significance difference across criteria (p 0.128), major geographic regions (all p≥0.125) and varied less by publication year (p > 0.154), or study sample size (p>0.532). Substantial heterogeneities in the estimates across and within criteria were not always explained by major studies level characteristics. Artefactual publication bias was apparent across studies with WHO and IOTF criteria but not for CDC criterion. Interpretations: Overweight and obesity are common among primary school-going African children, particularly those attending urban schools and in private schools. Our results support the urgent need for intervention strategies, policies and programmes to address the lifestyle changes contributing to the growing excess weight in children in African settings. Funding Statement: There was no funding source for this study. The corresponding author had full access to all the data in the study and had final responsibility for the decision to submit for publication. Declaration of Interests: The authors declare no competing interest.