Mitigating the impact of intergenerational risk factors on stunting: Insights from the Grow Great Community Stunting Survey

A large international body of research investigates the determinants of stunting in young children, but few studies have considered which of these factors are the most important predictors of stunting. The relative importance of predictors of stunting has not been explored in South Africa. We examine the predictors of height-for-age and stunting and which of these are most important in children under 5 years of age in seven of the most food-insecure districts in South Africa, using data from the Grow Great Community Stunting Survey of 2022. We use dominance analysis and variable importance measures from conditional random forest models to assess the relative importance of predictors. In line with studies from other countries, we find that intergenerational and socioeconomic factors – specifically maternal height, birth weight and asset-based measures of socioeconomic status – are the most important predictors of height-for-age and stunting in these districts. Given our finding that intergenerational and socioeconomic factors are the most important predictors of stunting, we explore whether any other factors moderate (weaken) the relationship between these factors and child height, using conditional inference trees and moderation analysis. We find that being on track for vitamin A and deworming, adequate sanitation, a diverse diet and good maternal mental health moderate the effect of birth weight or mother's height, having a stronger association with height-for-age in children with lower birth weights and with shorter mothers. Though any impacts are likely to be small relative to the impact of intergenerational risk factors, these moderating factors may provide promising avenues for mitigating the intergenerational transmission of stunting risk in South Africa.