Objective To determine the prevalence and differentials of overweight/obesity (body mass index (BMI)-for-age z-score >2) in preschool children in Sub-Saharan Africa (SSA).

Design Cross-sectional study.

Setting The study was conducted on the basis of the data of 26 Demographic and Health Surveys carried out in SSA since 2010.

Participants The records of 155 726 children aged 0–59 months were included in the analysis.

Primary outcome Overweight/obesity.

Results The prevalence of overweight/obesity was 6.8% (95% CI 6.7% to 6.9%). Among the countries represented, higher figures were reported in Sierra Leone (16.9%), Comoros (15.9%) and Malawi (14.5%), whereas lower prevalence was found in Ethiopia (3.0%), Togo (2.6) and Senegal (2.0%). In 11 of the countries, overweight/obesity was more prevalent than wasting. It is estimated that in the whole subcontinent, 10.7 million children were affected by the problem. The prevalence of overweight/obesity was slightly higher in boys than in girls. Overweight/obesity was three times more frequent in stunted children than in normal children. The risk also significantly increased with increasing maternal BMI and birth weight and decreased with increasing maternal age, maternal education, child's age and number of siblings. On the other hand, no significant association was observed with national gross domestic product per capita, place of residence (urban–rural) and household wealth index.

Conclusion Childhood overweight/obesity has become a sizeable problem in the subcontinent.