Comparison of the effectiveness of body mass index and body fat percentage in defining body composition

Introduction Body mass index (BMI) has limited diagnostic performance due to its inability to discriminate between fat and lean mass. This study was conducted to compare the effectiveness of body fat percentage (BFP) against BMI in defining body composition. Methods A cross-sectional study was conducted on students aged 17-30 years in Melaka, Malaysia. Basic anthropometric measurements were acquired using a manual weighing scale, measuring tape and a fixed stadiometer. BFP was calculated using the United States Navy formula. Data was tabulated and analysed using Epi Info and Statistical Package for the Social Sciences software. Pearson's correlation coefficient and Kappa values were used. A p-value < 0.05 was considered statistically significant. Results Out of the 490 subjects recruited, 43% of males and 24.6% of females were found to be overweight, while 14.3% of males and 7.8% of females were obese, when calculated using BMI. However, 8.9% of males and 22.8% of females were considered obese based on the BFP. Conclusion BFP plays a more important role in distinguishing between healthy and obese individuals, as it has a greater ability to differentiate between lean mass and fat mass compared to BMI.