Comparison of Bioelectrical Impedance Analysis and Skinfold Thickness to Determine Body Fat Percentage among Young Women

Body composition analysis (BCA) measurements are the quantitative methods to evaluate nutritional status and adiposity. There is an increased need for BCA methods, especially calculation of body fat percentage with better sensitivity and precision. This study is focused on estimation of body fat percentage using two methods. Objective of the study was to compare body fat percentage obtained using four-site skinfold thickness (SFT) measurement with bioelectrical impedance analysis (BIA) of young women. The 4-site SFTs were measured at triceps, bicep, subscapular and suprailiac region, using Harpenden caliper. Body fat percentage was computed using sum of skinfolds and Durnin-Womersley equation. BIA was done using a body composition analyzer. Statistical analysis including the Bland-Altman plot was performed in SPSS software v.23.0 and MS Excel. A total of 310 women (age 18-25 years) participated in this cross-sectional study. Mean BMI of participants was 22.2±5.05 kg/m2. Body fat percentage from skinfold thickness and BIA techniques were 32.79±5.048% and 33.85±5.32% respectively. Although there was a positive correlation (p<0.01) observed between the two methods, Bland-Altman plot indicated a proportional bias (r=0.176, p<0.05). It also showed difference of agreement between SFT & BIA methods. BIA overestimates the body fat percentage with limits of agreement range-5.33% to 3.28%. Our study reported that BIA overestimates body fat percentages compared to SFT. However, the two methods are not interchangeable. Evaluating anthropometric measurements is considered useful method as it controls regional changes of subcutaneous adiposity, whereas BIA technique can be used for its practical applicability.