Variable

All

Boys

Girls

Mean ± SD

BMI at birth

BMI

12.63 ± 1.25

12.62 ± 1.22

12.66 ± 1.29

BMI at 3 years old

BMI

15.69 ± 1.15

15.78 ± 1.18

15.60 ± 1.11

BMI z-score*

0.10 ± 0.87

0.10 ± 0.91

0.11 ± 0.82

Level 2: Individual: n = 899

Year of birth

2006

68 (7.6%)

38 (8.2%)

30 (6.9%)

2007

292 (32.5%)

154 (33.1%)

138 (31.9%)

2008

317 (35.3%)

149 (32.0%)

168 (38.8%)

2009

222 (24.7%)

125 (26.8%)

97 (22.4%)

Sex

Male

466(51.8%)

Female

433(48.2%)

Maternal pre-pregnancy BMI

20.83 ± 3.22

20.78 ± 3.16

20.89 ± 3.29

Gestational age

Full term

786(94.2%)

406 (92.9%)

380 (95.7%)

Pre-term

41(4.9%)

29 (6.6%)

12 (3.0%)

Post term

7(0.8%)

2 (0.5%)

5 (1.3%)

Mother employed

No

315 (43.6%)

165 (43.0%)

150 (44.3%)

Yes

402 (55.6%)

216 (56.3%)

186 (54.9%)

Other

6 (0.8%)

3 (0.8%)

3 (0.9%)

Birth weight

3.05 ± 0.44

3.06 ± 0.45

3.04 ± 0.43

Low birth weight

73 (9.0%)

38 (8.4%)

35 (8.5%)

Parity

First child

288 (40.3%)

149 (39.4%)

139 (41.3%)

Others

427 (59.7%)

229 (60.6%)

198 (58.7%)

Twin

Yes

14(7 pairs) (1.6%)

12 (6 pairs) (2.6%)

2 (1 pair) (0.5%)

Family Structures

Nuclear family

471 (67.4%)

254 (68.1%)

217 (66.6%)

Extended family

212 (30.3%)

116 (31.1%)

96 (29.5%)

Single parent family

16 (2.3%)

3 (0.8%)

13 (4.0%)

Maternal smoking

Yes

39 (5.6%)

20 (5.4%)

19 (5.7%)

Enrolment in a nursery at 4 months of age

Yes

29 (4.0%)

14 (3.7%)

15 (4.4%)

Feeding behaviour until 4 months

Breast milk

327 (45.0%)

167 (43.6%)

160 (46.5%)

Formula

109 (15.0%)

52 (13.6%)

57 (16.6%)

Both

291 (40.0%)

164 (42.8%)

127 (36.9%)