Table 1 Background characteristics of the cross-sectional and prospective study samples (mean (SD) unless otherwise specified)
Cross-sectional samples | Prospective sample | |||||||
|---|---|---|---|---|---|---|---|---|
9-y-olds | n | 15-y-olds | n | Baseline | n | Follow-up | n | |
Girls | 49.4% | 51.0% | 48.9% | 48.9% | ||||
Age (years) | 9.6 (0.4) | 2366 | 15.3 (0.6) | 1554 | 9.6 (0.4) | 517 | 15.2 (0.7) | 517 |
Height (cm) | 138.7 (6.6) | 2342 | 169.6 (8.3) | 1490 | 139.1 (6.4) | 515 | 169.8 (8.4) | 477 |
Weight (kg) | 33.9 (6.8) | 2343 | 60.7 (11.4) | 1474 | 33.4 (6.3) | 515 | 59.8 (10.5) | 469 |
BMI (kg∙m−2) | 17.5 (2.6) | 2340 | 21.0 (3.3) | 1473 | 17.2 (2.4) | 515 | 20.7 (3.0) | 469 |
SES | ||||||||
Low | 6.8% | 153 | 5.9% | 82 | 5.8% | 29 | 5.8% | 29 |
Middle | 37.7% | 843 | 38.8% | 543 | 35.5% | 179 | 35.5% | 179 |
High | 55.5% | 1243 | 55.4% | 776 | 58.7% | 296 | 58.7% | 296 |
Acc. WT (min/d) | 804.5 (64.5) | 2366 | 840.2 (89.5) | 1554 | 817.4 (66.7) | 517 | 824.5 (84.5) | 517 |
MVPA (min/d) | 92.1 (30.6) | 2366 | 68.6 (26.3) | 1554 | 98.2 (33.3) | 517 | 69.5 (25.6) | 517 |
Sleep (hrs/d)a | 9.7 (0.8) | 2102 | 8.1 (0.9) | 1165 | 10.3 (0.6) | 478 | 7.5 (0.7) | 382 |
Screen time (hrs/d) | 2.6 (1.3) | 2081 | 3.9 (1.6) | 1209 | 2.4 (1.3) | 476 | 3.9 (1.6) | 399 |
Active transport | ||||||||
0–5 min/d | 43.7% | 926 | 52.3% | 652 | 38.6% | 188 | 48.9% | 204 |
6–15 min/d | 35.8% | 757 | 36.1% | 450 | 40.5% | 197 | 36.7% | 153 |
≥ 16 min/d | 20.5% | 434 | 11.6% | 1247 | 20.9% | 102 | 14.4% | 60 |
Sports/exercise | ||||||||
≤ 2 h/week | 36.1% | 762 | 30.2% | 373 | 30.8% | 150 | 28.6% | 117 |
3–7 h/week | 53.1% | 1119 | 46.8% | 577 | 56.1% | 273 | 43.8% | 179 |
≥ 8 h/week | 10.8% | 228 | 23.0% | 284 | 13.1% | 64 | 27.6% | 113 |