Table 1.

Body Mass Index (BMI), kg/m²) by Age from 8 to 18 Years and Decades of Birth

Age	Birth Decade (BD)
(years)	1960≤BD<1970			1970≤BD<1980			1980≤BD<1990			1990≤BD<2000
Boys	n	mean	std	n	mean	std	n	mean	std	n	mean	std
8≤age<9	68	16.18 *	1.99	57	15.94 *	1.83	43	16.06	2.51	35	16.90	3.01
9≤age<10	65	16.73 *	2.56	46	16.87 *	2.56	43	17.00	3.24	30	17.61	4.31
10≤age<11	73	17.02 *	2.44	62	16.94 *	2.89	46	17.71	3.80	37	18.77	5.05
11≤age<12	73	17.53 *	2.61	59	17.77 *	3.28	48	18.06	3.71	36	18.41	3.92
12≤age<13	70	18.15 *	3.04	60	18.22 *	3.27	41	19.15	4.41	41	20.30	4.80
13≤age<14	64	18.76 *	3.47	58	19.01 *	3.46	44	19.73	4.53	30	20.65	4.66
14≤age<15	64	19.64 *	3.56	59	20.06 *	3.73	51	20.97	4.77	29	22.12	5.77
15≤age<16	61	20.19 *	3.36	58	20.76 *	4.10	41	21.05	4.38	29	22.72	5.22
16≤age<17	52	21.38 *	4.26	43	20.95 *	4.20	40	22.20	5.01	20	22.70	4.75
17≤age<18	48	21.73 *	4.40	43	21.40 *	4.29	44	22.26	4.45	15	22.18	3.79
Girls
8≤age<9	72	16.39 *	2.08	51	16.78 *	2.14	57	16.52 *	2.48	34	18.35	6.65
9≤age<10	81	16.93 *	2.27	51	17.11 *	2.49	54	16.83 *	2.67	27	18.10	3.70
10≤age<11	73	17.54 *	2.46	53	17.94 *	2.59	55	17.84 *	3.00	24	18.70	3.67
11≤age<12	75	17.96 *	2.45	55	18.38 *	2.83	57	18.66 *	3.42	19	18.81	3.14
12≤age<13	74	19.06 *	2.84	52	19.59 *	3.19	57	19.83 *	3.64	18	19.83	3.44
13≤age<14	73	20.13 *	2.97	51	20.10 *	2.90	46	20.69 *	3.83	20	20.63	2.88
14≤age<15	55	21.05 *	3.05	38	20.39 *	3.35	46	21.88 *	3.98	15	22.57	3.26
15≤age<16	45	21.32 *	3.31	45	21.09 *	3.03	28	22.30 *	3.82	19	22.81	3.69
16≤age<17	53	21.90 *	2.99	42	21.37 *	3.27	40	22.29 *	3.77	11	22.54	4.51
17≤age<18	55	21.63 *	3.38	38	21.65 *	2.67	48	23.87 *	5.32	11	23.37	5.29

^*Mean BMI significantly less than mean BMI for 1990–2000 (p-value < 0.05).