Table 3.

Differences in values of BMI-percentiles (in BMI-units) between the two study populations NHS (1966/69) and Young-HUNT (1995/97)¹

	Boys					Girls
Age	14	15	16	17	18	14	15	16	17	18
Percentiles(a)
2.5	-0.2	-0.16	-0.43*	-0.55	-0.87*	-0.6*	-0.28	-0.07	-0.04	-0.07
5	-0.11	-0.14	-0.18	-0.14	-0.93*	-0.45*	-0.36	-0.24	-0.12	0
10	0	-0.15	-0.09	-0.10	-0.59*	-0.39*	-0.03	-0.26	-0.09	0.02
15	-0.01	-0.16	-0.11	-0.04	-0.15	-0.37	-0.08	-0.32	0	0.09
25	0.08	-0.10	-0.17	0.15	0.11	-0.28	0.03	-0.1	0.14	0.04
50	0.28*	-0.05	0.21	0.39*	0.35	-0.2	0.26	0.02	-0.09	0.19
75	0.94	0.43	0.49	0.77	0.97	0.36	0.16	0.13	0.54	0.51
85	1.62	1.08	0.83	1.14	1.74	0.89	0.08	0.57	1.79	1.14
90	2.28*	1.89*	1.29*	1.72*	2.26*	0.9*	0.53	0.96	1.03	1.73*
95	2.94*	2.36*	3.04*	2.89*	2.73*	1.53*	1.15	1.4*	1.72*	2.71*
97.5	3.33*	2.78*	3.31*	4.43*	5.08*	2.24*	0.75	2.13*	2.29*	4.38*

* p < .05 for mean difference equal to 0.

¹ Since height and weight were rounded off, to the nearest cm and half kg, there is measurement error in the tabulated differences. Its standard deviation has been computed as 0.07, 0.03, and 0.12, BMI-units respectively, for the 2.5, 50, and 97.5 percentiles.