Background/Purpose The validity of body composition assessment tools for school-aged children is an important applied research topic. Previous studies found the mean differences of %BF values measured from Foot-to-foot (F-BIA) and hand-to-hand (H-BIA) analyzers in Japanese men and American college male students. This investigation was to examine if there had differences in %BF estimates measured by two analyzers in middle school students.
Method Subjects were the 6th-grade students (n=146). The study was explained and the informed consent was signed before testing. % body fat measures were taken by using Omron Body Fat Analyzers. Subjects were measured following the manufacturer instructions and other guidelines. Pearson's method was used to examine correlations. Differences in variables were tested using t-test. Significant level was set at p≤0.05. Values are presented as means±SD. Data were analyzed using SPSS for Windows.
Analysis/Results Subjects' mean age was 11.91±0.43 yrs. The results indicated a significant mean difference in %BF estimated by two devices: 29.23±7.19% vs. 23.90±8.40% (girls vs. boys, p<0.001) for upper-body and 29.63±8.98% vs. 17.98±7.07% (p<0.001) for lower-body. There was a high relationship between %BF estimates from two devices for girl-group (r=0.75, p<0.001), but a low relationship for boy-group (r=0.41, p<0.001). Significant differences between two %BF values (p<0.001) were noted only in boy-group.
Conclusions Our results indicated that %BF estimates was much higher by using the H-BIA than the F-BIA in the male students, but almost identical for female students. It is strongly recommended to use the same BIA device consistently for assessing %BF in this population.