Assessing the nexus between household socioeconomic status and stunted-growth recovery among post-infant and early-adolescent children in South Africa

Abstract

Stunting, a condition characterised by hindered physical and cognitive development, results from inadequate nutrition, recurrent infections, and limited psychosocial stimulation during early childhood. It has long-term health, cognitive, and economic consequences such as affected individuals earning over 20% less than average in adulthood, reinforcing cycles of poverty. Global efforts have prioritized reducing stunting, particularly during the first 1,000 days of life. However, adolescence – another critical developmental window – receives little to no policy and investment attention in South Africa. While stunting prevalence is well documented, limited research explores how household socioeconomic conditions influence growth outcomes beyond infancy, into adolescence. This study aims to address this critical knowledge gap by investigating how household socio-economic conditions influence stunting status beyond infancy and early adolescence. Using longitudinal data from the National Income Dynamics Study (NIDS) in South Africa, the analysis explores associations between household socio-economic status (HHSES) and child stunting trajectories. HHSES was measured through a composite index derived from principal component analysis (PCA) based on household assets and access to basic services. Height-for-age Z-scores (HAZ) were analysed across five waves, tracking a total of 485 children from age 2 to early adolescence at age 11. Children identified as stunted at age two showed marked improvements in linear growth over time. Longitudinal analysis (transition matrix) revealed that about half of the children initially classified as severely stunted (HAZ < -3) had recovered by the final wave, while between 60–80% of those moderately stunted at baseline (2<HAZ<-3) achieved non-stunted status by ages 7, 9, and 11, across the cohorts. Multinomial logistic regression showed a strong association between household socio-economic status (HHSES) and recovery from stunting. Improvements in HHSES were linked to a significantly lower risk and decline of stunting (RRR = 0.289, p = 0.030; RRR = 0.304, p = 0.038), while children in low-HHSES households remained at a significantly greater risk (RRR = 3.96, p = 0.041). These findings challenge the notion that stunting is irreversible beyond infancy and highlight the importance of ongoing childhood interventions, particularly addressing household socioeconomic conditions, and targeting adolescence as the second window of opportunity.