Table 1.

Age-adjusted characteristics of 134 adolescent males, NHANES III (Phase I), 1988–1991

	12–15 Year Olds			16–19 Year Olds
	Non-Hispanic white	Non-Hispanic black	Mexican-American	Non-Hispanic white	Non-Hispanic black	Mexican- American
No. of participants	14	17	26	19	21	37
Age (yr), mean (95% CI)
	13.2	13.6	13.8	17.9	17.4	17.5
	(12.5, 13.8)	(12.8, 14.5)	(13.4, 14.2)	(17.1, 18.6)	(17.0, 17.8)	(17.1, 17.9)
Body fat (%), mean (95% CI)
	21.4	16.7	21.6	24.9	14.1	23.6
	(17.2, 25.6)	(9.2, 24.1)	(17.7, 25.5)	(16.9, 32.8)	(11.5, 16.8)	(21.3, 26.0)
Waist circumference (cm), mean (95% CI)
	76.7	74.7	75.2	85.1	76.8	81.6
	(70.8, 82.7)	(65.6, 83.8)	(70.0, 80.3)	(78.3, 92.0)	(73.9, 79.7)	(77.6, 85.7)
Weight (lb), mean (95% CI)
	123.6	123.6	123.3	170.6	156.3	155.5
	(110.2, 137.0)	(107.4, 139.7)	(107.5, 139.0)	(152.2, 189.1)	(146.4, 166.3)	(143.0, 167.9)
Height (in), mean (95% CI)
	65.0	64.8	63.1	70.0	68.9	68.0
	(63.5, 66.4)	(63.4, 66.2)	(61.8, 64.5)	(69.4, 70.6)	(67.3, 70.5)	(67.3, 68.6)
Cotinine level (ng/mL)a, mean (95% CI)
	1.5	0.5	0.2	1.7	0.5	1.8
	(0.8, 2.9)	(0.1, 1.5)	(0.1, 0.4)	(0.4, 8.1)	(0.2, 1.5)	(0.7, 4.7)
Physical activity, times/wk (%)
0–2	10.6	2.6	3.2	10.8	2.4	10.5
≥3	89.4	97.4	96.8	89.2	97.6	89.5
Tanner stage – pubic hair (%)
Stages 1 and 2	37.1	6.1	35.5	0.0	0.0	0.0
Stages 3 and 4	29.1	64.8	41.1	9.7	4.8	18.2
Stage 5	33.8	29.1	23.4	90.3	95.2	81.8
Tanner stage – genitalia (%)
Stages 1 and 2	23.9	5.5	13.1	0.0	0.0	0.0
Stages 3 and 4	52.8	54.9	66.4	10.1	0.0	19.6
Stage 5	23.3	39.6	20.5	89.9	100.0	80.4

^aGeometric mean based on log-transformed cotinine level (an indicator of exposure to tobacco smoke)