Table 2.

Fat mass, fat-free mass, percentage of body fat, lean body mass, bone mineral contents, and body mass by BIA and DXA.

	BIA	DXA	CE (95% CI)	SEE	MD
Boys (n = 226)
FM (kg)	7.6 ± 6.2	7.9 ± 4.4	− 0.28 ± 2.37 (− 0.59, 0.03)	1.284	1.36
FFM (kg)	35.7 ± 7.6	35.7 ± 8.8	0.07 ± 2.01 (− 0.19, 0.34)	1.704	0.77
PBF (%)	16.0 ± 8.3	17.6 ± 6.1*	− 1.57 ± 4.47 (− 2.16, − 0.99)	3.207	4.75
LBM (kg)	33.9 ± 7.1	34.5 ± 8.5*	− 0.63 ± 2.08 (− 0.90, − 0.35)	1.681	0.82
BMC (kg)	1.8 ± 0.5	1.1 ± 0.3*	0.70 ± 0.20 (0.68, 0.73)	0.115	0.15
BM (kg)	43.3 ± 11.9	43.6 ± 11.5*	− 0.21 ± 0.48 (− 0.27, − 0.14)	0.310	0.00
Girls (n = 217)
FM (kg)	9.4 ± 4.2	9.4 ± 3.6	0.01 ± 1.24 (− 0.16, 0.17)	0.963	0.66
FFM (kg)	32.8 ± 4.5	33.1 ± 5.2*	− 0.36 ± 1.09 (− 0.51, − 0.21)	0.918	0.38
PBF (%)	21.4 ± 5.9	21.5 ± 4.9	− 0.18 ± 2.81 (− 0.55, 0.20)	2.321	2.70
LBM (kg)	30.9 ± 4.2	32.0 ± 5.0*	− 1.11 ± 1.15 (− 1.27, − 0.96)	0.904	0.41
BMC (kg)	1.9 ± 0.3	1.1 ± 0.3*	0.76 ± 0.17 (0.74, 0.78)	0.119	0.16
BM (kg)	42.2 ± 8.1	42.5 ± 7.9*	− 0.35 ± 0.32 (− 0.39, − 0.31)	0.263	0.03
All (n = 443)
FM (kg)	8.5 ± 5.4	8.6 ± 4.1	− 0.14 ± 1.91 (− 0.32, 0.04)	1.187	1.10
FFM (kg)	34.3 ± 6.4	34.4 ± 7.4	− 0.14 ± 1.64 (− 0.29, 0.14)	1.433	0.63
PBF (%)	18.6 ± 7.7	19.5 ± 5.9*	− 0.89 ± 3.81 (− 1.25, − 0.53)	2.830	3.70
LBM (kg)	32.4 ± 6.0	33.3 ± 7.1*	− 0.87 ± 1.7 (− 1.02, − 0.71)	1.440	0.69
BMC (kg)	1.9 ± 0.4	1.1 ± 0.3*	0.73 ± 0.19 (0.71, 0.75)	0.117	0.16
BM (kg)	42.8 ± 10.2	43.1 ± 9.9*	− 0.28 ± 0.42 (− 0.32, − 0.24)	0.295	0.00

Data are means ± standard deviations.

BIA, bioelectrical impedance analysis; DXA, dual energy X-ray absorptiometry; CE, constant error (BIA minus DXA value); CI, confidence interval; SEE, standard error of estimate; MD, minimum difference; FM, fat mass; FFM, fat-free mass; PBF, percentage of body fat; LBM, lean body mass; BMC, bone mineral contents; BM, body mass.

*p < 0.05 (Paired t test between BIA and DXA).