Abstract:
Body fat assessment using 4-compartment (4C) model is known to be the
criterion method, due to the minimal assumptions involved. However, the common
standards for body fat assessment are either underwater weighing (UWW), dual energy
X-ray apsorptiometry (DEXA) or deuterium oxide (D2O). A comparison of each single
method with the 4C is needed. This study is the first of its kind to be carried out in the
Thai population. Hence, the purpose of this study was to compare body fat assessment
using commonly used single methods i.e. UWW, DEXA and D2O with 4C model in
Thai adolescents. Fifty-six secondary school students (29 males and 27 females), aged
16-19 years with normal nutritional status using the criteria weight-for-height within +
1 SD of Thai growth curve were selected. The 4-comparment model was calculated
using body density (Db), bone mineral content (BMC) and total body water (TBW).
Results indicated that the percentages of body fat obtained from UWW and
DEXA (males only) were not significantly different from that determined by the 4Cmodel.
Pearson correlation coefficients of %BF between 4C-model and UWW, 4C
model and DEXA and 4C model and D2O were 0.92, 0.76, 0.52 in male and 0.87,
0.77, 0.74 in female subjects, respectively. The standard error of estimation (SEE)
showed within the acceptable range; being 1.22, 2.05, 2.71 % in males and 1.18, 1.46,
1.54 % in females for UWW, DEXA and D2O, respectively. Bland-Altman analysis
was used to assess agreement between 4C with single methods. Regarding each
method, UWW and DEXA tended to underestimate body fat in leaner subjects and
overestimate it in the fatter subjects. In contrast, D2O method overestimate body fat in
leaner subjects and underestimate it in fatter subjects.
It is suggested from this study that when 4C technique is not possible UWW
technique could be used as an alternative method for assessment of body fat in both
normal weight male and female adolescents and DEXA technique should be used for
male adolescents only.