Table 3. Changes in the body composition measured by bioelectrical impedance analysis system.

Variable			Placebo (n = 37)				Collagen (n = 37)				p value†
			Baseline	12 weeks	Changes	p value*	Baseline	12 weeks	Changes	p value*
Weight (kg)			65.1 ± 8.1	65.0 ± 8.5	−0.1 ± 1.5	0.739	64.3 ± 8.1	63.8 ± 8.0	−0.5 ± 1.4	0.048‡	0.260
BMI (kg/m2)			25.7 ± 2.3	25.7 ± 2.3	−0.1 ± 0.6	0.647	25.9 ± 2.0	25.6 ± 2.0	−0.2 ± 0.6	0.022‡	0.204
WHR			0.91 ± 0.05	0.90 ± 0.04	−0.00 ± 0.02	0.170	0.92 ± 0.04	0.91 ± 0.04	−0.01 ± 0.02	0.002§	0.146
Visceral fat area (m2)			110.5 ± 29.3	108.1 ± 27.6	−2.4 ± 8.3	0.084	116.3 ± 32.3	110.6 ± 29.2	−5.7 ± 8.7	0.000∥	0.106
Fat-free mass (kg)			42.5 ± 7.0	42.7 ± 7.1	0.2 ± 0.9	0.246	41.2 ± 7.0	41.4 ± 6.9	0.2 ± 1.95	0.131	0.753
Skeletal muscle mass (kg)			23.2 ± 4.2	23.3 ± 4.3	0.1 ± 0.5	0.350	22.4 ± 4.3	22.6 ± 4.2	0.1 ± 0.6	0.147	0.643
Fat mass
	Whole body
		Body fat mass (kg)	22.5 ± 4.6	22.5 ± 4.5	−0.0 ± 1.2	0.881	23.1 ± 4.9	22.4 ± 4.5	−0.7 ± 1.2	0.002§	0.021‡
		Percent body fat (%)	34.8 ± 5.6	34.4 ± 5.2	−0.3 ± 1.3	0.121	36.0 ± 5.9	35.2 ± 5.6	−0.8 ± 1.5	0.002§	0.148
	Trunk
		Body fat mass (kg)	11.6 ± 2.4	11.4 ± 2.3	−0.2 ± 0.7	0.159	11.9 ± 2.3	11.4 ± 2.1	−0.4 ± 0.7	0.001§	0.100
		Percent body fat (%)	249.9 ± 52.9	247.2 ± 53.3	−2.7 ± 15.2	0.285	260.9 ± 47.2	251.6 ± 44.5	−9.3 ± 14.7	0.000∥	0.064

Data are presented as means ± standard deviations.

The participants take the collagen peptide supplement (15 g/day) or placebo once daily during the 12-week intervention period.

BMI, body mass index; WHR, waist–hip ratio.

^*Significance was determined by the paired t-test, p < 0.05; ^†Significance was determined by the independent t-test, p < 0.05; ^‡p < 0.05; ^§p < 0.01; ^∥p < 0.001.