Table 1.

Baseline characteristics in 1996 of preadolescents and adolescents in the Growing Up Today Study by sex

	Females (N=7052)*	Males (N=5487)*
	Mean (SD), n (%)	Mean (SD), n (%)
Mean age, years (SD)	11.9 (1.6)	11.8 (1.5)
Mean body mass index, kg/m2 (SD)	19.1 (3.6)	19.2 (3.5)
Mean body mass index z score (unit)	0.10 (1.0)	0.25 (1.1)
Mean weight concern (SD)	2.1 (1.1)	1.6 (0.8)
Tanner stage (%)†
Stage 1	1466 (21.2%)	1394 (26.2%)
Stage 2	1503 (21.7%)	1561 (29.3%)
Stage 3	1188 (17.2%)	1026 (19.3%)
Stage 4	1640 (23.7%)	986 (18.5%)
Stage 5	1115 (16.1%)	355 (6.7%)
Menstral status (% yes)	2270 (32.4%)	NA

^*total n differs slightly for each variable

^†Tanner stage of pubic hair development

NA, not applicable

SD, standard deviation