Do Anthropometric Health Risk Indicators of South African Primary School Children Require National Growth Charts? Insights from the NW-CHILD Study

Abstract

Abstract Background/Objectives: Growth monitoring and screening are vital indicators for child wellness. Controversy exists regarding the use of national versus international growth charts for school-going children. This study investigated the suitability of existing global references, considering the influence of age, gender, and socioeconomic status (SES), and the specific growth patterns across multiple anthropometric health indicators (AHIs). Methods: A total of 349 children (boys = 165, girls = 184, low SES = 201, high SES = 148) were measured longitudinally at ages 6, 9, and 12 years while attending primary school. AHI included stature, body mass, body mass index (BMI), body fat percentage (BFP), skinfold thickness, skeletal muscle, and waist circumference (WC). Results: Three-way interaction effects were found for age, gender, and SES on WC and skeletal muscle (p = 0.05). Several two-way interactions emerged for age and gender (height, BMI, skeletal muscle; p < 0.01), as well as age and SES (height, BMI, skeletal muscle; p < 0.01) and gender Children 2026, 13, 372 https://doi.org/10.3390/children13030372 Children 2026, 13, 372 2 of 26 and SES (height, skeletal muscle, WC, p < 0.05). Cut-points for height, body mass, and BMI at the median, compared to universal standards, indicate that the total group fell at, or slightly above, World Health Organization (WHO) standards. The low SES group aligned with WHO standards, whereas the high SES group trended above the reference values at most points. Conclusions: The WHO growth standards are suitable for general monitoring in South African children aged 6-12 years but provide limited context-specific interpretation across age, gender, and socioeconomic backgrounds. National age-, gender-, and SES-specific growth references, incorporating additional anthropometric indicators, are needed to support locally relevant screening.