Body mass index and body fat percentage in determining overweight and obesity among school going adolescents of urban Mysuru, Karnataka: a cross-sectional study

Abstract

Background: Overweight and obesity among adolescents is an important global health issue. BMI is the commonly used screening tool but there can be under or over estimation. Body fat percentage estimation using bioelectrical impedance analysis is easy and non-invasive technique and along with BMI can provide a better predictive capacity. Considering importance of early detection of overweight and obesity in adolescents, present study was done among school going adolescents of urban Mysore. Objectives were to determine the prevalence of overweight and obesity using BMI and body fat percentage among school going adolescents and to determine the relationship between BMI and body fat percentage. Methods: A cross sectional study was conducted among 706 school students in urban Mysuru aged 13-16 years and semi-structured proforma was used to collect data. Anthropometric measurements taken and Omron HBF 701 Karada scan complete digital body composition monitor used to measure body fat percentage. BMI-for-age (5-19 years) WHO 2007 and McCarthy’s body fat reference used to classify participants. Statistical tests like Pearson’s correlation used. Results: According to BMI, 9.8% and 5% were overweight and obesity prevalence respectively and according to body fat percentage19.4% were over fat and 17.1% were obese. Among adolescents with normal BMI, 18.4% and 11.9% were classified as overfat and obese respectively according to body fat percentage. The correlation between BMI and body fat percentage was statistically significant. Conclusions: Higher prevalence of obesity seen according to body fat percentage cut-offs than according to BMI.