Weight and length at birth in relation to body mass index and prevalence of obesity at around 20 years of age

	No of subjects (n=4300)	*Mean body mass index^(95% CI)**	No of subjects with body mass index 30	Prevalence of obesity (%) (95% CI)

Birth weight (g)
2500	171	22.7 (22.2 to 23.2)	6	3.5 (0.7 to 6.3)
2501-3000	604	23.0 (22.7 to 23.2)	20	3.3 (1.9 to 4.7)
3001-3250	607	23.1 (22.8 to 23.4)	22	3.6 (2.1 to 5.1)
3251-3500	845	23.2 (23.0 to 23.5)	37	4.4 (3.0 to 5.8)
3501-3750	776	23.7 (23.4 to 23.9)	47	6.1 (4.4 to 7.7)
3751-4000	677	23.7 (23.4 to 24.0)	37	5.5 (3.8 to 7.2)
4001-4500	515	23.7 (23.4 to 23.9)	18	3.5 (1.9 to 5.1)
4501	105	24.8 (24.1 to 25.6)	12	11.4 (5.2 to 17.6)
Length at birth (cm)
46	75	22.1 (21.8 to 23.5)	3	4.0 (0.0 to 8.5)
47-48	168	22.7 (22.2 to 23.2)	5	3.0 (0.4 to 5.6)
49-50	657	23.2 (23.0 to 23.5)	31	4.7 (3.1 to 6.3)
51-52	1329	23.2 (23.1 to 23.4)	48	3.6 (2.6 to 4.6)
53-54	1338	23.5 (23.3 to 23.7)	66	4.9 (3.8 to 6.1)
55-56	609	23.9 (23.6 to 24.1)	36	5.9 (4.0 to 7.7)
56	120	24.1 (23.4 to 24.7)	10	8.3 (3.3 to 13.4)

^*Weight/(height)² Information on length at birth was missing for four subjects.