Smoothened percentiles for height, weight and body mass index of urban school going adolescents aged 11-17 years in national capital territory region of Delhi, India.

Abstract

The aim of the study was to estimate centiles by using improved statistical smoothing procedure, the Box-Cox power-exponential (BCPE) method, in urban northern Indian adolescents aged 11-17 years. Data were collected cross-sectionally by measuring specific anthropometric features such as height, weight, and mid-upper arm circumference in school-based adolescents aged 11-17 years including both boys (n = 838) and girls (n = 788) enrolled in government educational institutions in urban Delhi. We used a state-of-the-art statistical methodology (BCPE method) to establish centile curves. The model fitted before smoothing revealed that weight, height, and BMI did not follow a normal distribution; both skewness and kurtosis were observed in all three variables. After correcting both skewness and kurtosis, estimated empirical percentile values showed a gradual increase in weight, height, and BMI in both boys and girls. Girls had higher weight and height than boys in initial ages and observed a steep increase in boys in both weight and height in later ages. BMI was higher in girls than boys and visibly higher during 14-16 years of age. The 50^th percentile value of BMI was smaller in all the ages in our study than that in other studies. Smoothened percentile values derived for BMI by using the state-of-the-art statistical methodology may help policymakers to promote better growth in urban adolescents.