Body Mass Index Correlates with Body Fat Percentage in Children and Adolescents in the Democratic Republic of the Congo: A cross sectional study

Abstract

Paediatric obesity is a worldwide health challenge and parameters to evaluate population obesity risk are needed. The purpose of this  study is to report on anthropometric measures for assessing obesity risk for children in subSaharan Africa and to confirm that measuring height and weight to calculate BMI can be used as a good indicator of obesity risk.

Materials and  Methods: This was a cross-sectional study of a sample of 1,442 students aged 6 to 18 years enrolled in schools in the city of Kinshasa, the capital of the Democratic Republic of Congo. These school children were selected using a multistage sampling method. BMI for-age-sex was calculated using WHO AnthroPlus and expressed in Z‑scores. Skinfolds were used to calculate percent body fat (%BF).
Data were analyzed using SPSS version 21.

Results: This study showed that the percentage body fat (BF) was higher in girls than in boys (20.5 ± 9.6 vs 12.4 ± 6.3 p< 0.001). The BMI  for girls was higher compared to boys (18.5 ± 3.7 vs 17.3 ± 3.0 p<0.001). The positive relationships were observed between percentage BF and BMI by sex. In addition, this relationship appears to be linear in nature. This relationship between BMI and percentage BF was  independent at age and increased with BMI. In this sample of youth from DRC, BMI appears to be a good proxy for adiposity. Across the total sample, more boys fall into the very low and low body fat category as compared to girls while proportionately more girls have body fat in the optimal range.

Conclusion: This study showed the positive relationships between BMI and percentage BF in children and adolescents in Sub-Saharan  Africa, particularly in DRC but given the difficulties of measuring skin folds, BMI appears to be a simple and easy measure.

Keywords: Body Composition, percentage of body fat, Overweight, Obesity, Adolescents, Children