Age categorization of overweight and obesity using waist circumference, waist height ratio and body mass index among children and youth in Nigeria

Background: Undernutrition and obesity co-exist in Nigeria. The aim of this study was to evaluate the distribution of overweight and obesity across different age groups using waist circumference, waist height ratio and body mass index in Nigerian children. Methods: Cross-sectional study involving 2,893 students aged 9-18 years (1,140 boys and 1,753 girls) using multistage cluster sampling design. Weight, height, Waist circumference (WC) were measured, body mass index (BMI), waist to height ratio (WHtR) were calculated. Data analyzed to get mean, SD, Spearman correlation coefficients were computed to examine the association between WC, WHtRandBMI. Result : The mean BMI, WC and WHtR were statistically significantly higher in girls than in boys. Using WC, 107 (6.1%) of the girls and 44(3.9%) of the boys, had abdominal obesity. Increased WHtR occurred in 11.5% of the girls and 8.0% of the boys respectively. Using BMI,32.9% of the youths were either overweight (OW) or obese (OB): 28.8% in boys and 35.5% in girls. 371 (21.2%) and 252 (14.4%) of the girls were OW and OB, while 191 (16.8%) and 137 (12.0%) of the boys had OW and OB. There was a progressive increase in the WC and BMI across the age groups. A strong positive correlation coefficient was noted between WC and BMI 0.77842, between WHtR and BMI 0.73281, and between WC and WHtR 0.82197 p< 0.0001. Conclusion : The prevalence of overweight and obesity in Nigerian children is increasing, higher in girls than in boys. We recommend that in addition to BMI, WC or WHtR should be used to assess central adiposity in children.