The relationship between stunting and overweight among children from South Africa: Secondary analysis of the National Food Consumption Survey--Fortification Baseline I.

Background: Globally, in children the prevalence of overweight and obesity is increasing, and this is associated with an increased risk of non-communicable diseases in adulthood. There is a need to examine the growing trends of overweight and obesity in children and their consequences in low- and middle-income countries.

Objectives: To describe the prevalence of, and determine the relationship between, stunting and overweight among children in two provinces of South Africa.

Methods: Secondary data analysis was conducted on anthropometric measurements of 36-119-month-old children from Gauteng and Mpumalanga provinces (N=519) participating in the South African National Food Consumption Survey--Fortification Baseline I (2005). The International Obesity Task Force (IOTF) body mass index (BMI) reference percentiles were used to determine overweight and obesity. The World Health Organization standards were used to derive z-scores.

Results: The prevalence of overweight was 12.0% (IOTF BMI≥25 kg/m2), including 3.7% obesity (IOTF BMI≥30 kg/m2). The predominantly urban Gauteng Province had a significantly higher prevalence of overweight children (14.1%) compared with Mpumalanga (6.3%) (p=0.0277). The prevalence of stunting was 17.0% (16.5% Gauteng, 18.2% Mpumalanga; p>0.05). There was a significant correlation (r=-0.32) between BMI and height-for-age z-scores (p<0.0001). In the obese group, 68.4% were stunted, while in the normal and underweight group only 13.6% were stunted.

Conclusions: Stunted children were more likely to be obese. Further research is necessary for clarity on the physiological mechanisms of this relationship. In the interim, prevention of stunting requires priority.