Comparison of the prevalence of overweight and obesity in 9-13 year-old children from two countries using CDC and IOTF reference charts

Abstract

Background and Objectives: The epidemic of obesity is frequently prevailing, certainly among pediatric inhabitants and could be influenced by environmental and heritable factors. So, the aim of this study was to compare the prevalence of overweight and obesity in 9-13 year old children from Nigeria and South Africa using the criteria of the Centres for Disease Control and Prevention (CDC) and International Obesity Task Force (IOTF) for obesity classification chart based on age and gender-specific BMI cut-off points. Materials and Methods: Anthropometric measurements were taken using standardised protocol and used to estimate body mass index (BMI) and waist-to-height ratio (WHtR) in 1361 South African and 1229 Nigeria school children aged 9-13 year old. Height, body weight, BMI and WHtR were examined for Nigerian and South African school children according to sample size and age category. The BMI for age was used to classify the children according to weight categories and by gender, after which the obesity prevalence using the BMI Category for cut-off points chart was performed by age and countries. Results: The results showed that 1.1% (IOTF) and 9.9% (CDC) of Nigerian children were overweight. Corresponding data for South African children were 1.8% (IOTF) and 10.0% (CDC). Obesity estimates for Nigerian and South African children slightly varied for IOTF classification (1.1, 0.7%), but were similar when CDC classification was used (5.1%). In contrast, the CDC standard indicated strikingly lower incidence of underweight among the South African (4.9%) and Nigerian (4.8%) children. Conclusion: The lack of consistency in body weight classification using CDC and IOTF chart raises the question as to the right classification to use to evaluate weight abnormalities in children and adolescents. The choice of cut-off point in assessing overweight and obesity in childhood and adolescence should be based on reliable judgment as this could undermine the integrity of epidemiological research data.