Proportions of different birthweight groups among children and adolescents according to different gender and different educational stages
| Variables | Normal weight (N=19 776) | Overweight/obesity (N=7233) | P value |
| Boys | <0.001 | ||
| LBW | 2120 (15.2) | 1075 (25.1) | |
| NBW | 7337 (52.7) | 1823 (42.7) | |
| HBW | 4460 (32.1) | 1376 (32.2) | |
| Girls | <0.001 | ||
| LBW | 186 (3.2) | 141 (4.8) | |
| NBW | 3362 (57.4) | 1650 (55.8) | |
| HBW | 2311 (39.4) | 1168 (39.4) | |
| Primary school | <0.001 | ||
| LBW | 428 (8.0) | 225 (11.1) | |
| NBW | 3476 (64.8) | 1190 (58.8) | |
| HBW | 1463 (27.2) | 609 (30.1) | |
| Middle school | <0.001 | ||
| LBW | 903 (12.8) | 753 (33.1) | |
| NBW | 3177 (44.9) | 873 (38.4) | |
| HBW | 2994 (42.3) | 649 (28.5) | |
| High school | <0.001 | ||
| LBW | 975 (13.3) | 238 (8.1) | |
| NBW | 4046 (55.2) | 1410 (48.1) | |
| HBW | 2314 (31.5) | 1286 (43.8) | |
HBW, high birth weight; LBW, low birth weight; NBW, normal birth weight.