BODY-FAT ESTIMATION IN CHILDREN BY MAGNETIC-RESONANCE-IMAGING, BIOELECTRICAL-IMPEDANCE, SKINFOLD AND BODY-MASS INDEX - A PILOT-STUDY

Objective: The aim of this study was to identify the clinical method t o estimate body fat which gave best correlation of total body fat and percentage body fat as measured on MRI. Methods: Magnetic resonance im aging (MRI) was used to estimate the total body fat volume and percent age body fat and this was compared with assessment by bioelectrical im pedance (BEI), skinfold thickness and body mass index (BMI) in 8- to 1 2-year-old children. Results: Total body fat measured on magnetic reso nance imaging (TBF-MRI) significantly correlated with body mass index, triceps and subscapular skinfolds, and percentage body fat estimation s by BEI, Multiple regression analysis showed that BMI and BEl togethe r gave the best prediction of total body fat as measured on MRI from t he equation: TBF-MRI=-25277.77+1457.61(BMI)+423.95 (%fat-BEI), with R- 2=0.89. Percentage body fat measurement from MRI, BEl and skinfold wer e not significantly different but their results were not interchangeab le, Linear regression of %body fat from MRI on those obtained from BEI and skinfold measurements showed a modest fit with R-2=0.6973 and 0.5 501, respectively. Conclusions: In children 8-12 years old, BMI gives a good estimation of the total body fat as measured on MRI, The estima tion will be improved when both BEI and BMI are used in the prediction . Bioelectrical impedance has a low correlation with total body fat an d its use alone in estimating total body fat is not recommended. Skinf old measurement also gives a reasonably good prediction of total body fat and addition of BMI and BEI does not improve the prediction, Both BEI and skinfold measurements give a modest prediction of %body fat me asured by MRI method.