Table 1.
Participants’ Characteristics.
| Characteristic | Total (n = 2578) | Boys (n = 1303) | Girls (n = 1275) | p | |||
|---|---|---|---|---|---|---|---|
| Mean (SD) | n (%) | Mean (SD) | n (%) | Mean (SD) | n (%) | ||
| Age | 12.7(2.2) | - | 12.7 (2.3) | - | 12.9 (2.1) | - | 0.01 |
| Race | |||||||
| Han | - - |
2505 (98.8) | - - |
1254 (50.1) | - - |
1251 (49.9) | 0.28 |
| Minority | 31 (1.2) | 19 (61.3) | 12 (49.8) | ||||
| Weight (kg) | 45.3 (11.8) | - | 46.7 (12.8) | - | 43.8(10.5) | - | 0.00 |
| Height (cm) | 155.1 (13.6) | - | 156.3 (15.1) | - | 153.8(11.9) | - | 0.00 |
| Children BMI category a | |||||||
| Underweight | - | 405 (15.7) | - | 175 (43.2) | - | 230 (56.8) | 0.00 |
| Normal | - | 1817 (70.5) | - | 881 (48.5) | - | 936 (51.5) | |
| Overweight | - | 328 (12.7) | - | 226 (68.9) | - | 102 (31.1) | |
| Obese | - | 28 (1.1) | - | 21 (75) | - | 7 (25) | |
| Breastfeeding (months) | |||||||
| 0 | - | 370 (16) | - | 185 (50) | - | 185 (50) | 0.80 |
| <6 | - | 364 (15.7) | - | 183 (50.3) | - | 181 (49.7) | |
| ≥6 | - | 1578 (68.3) | - | 800 (50.7) | - | 778 (49.3) | |
| Mother BMI | 22.2 (2.7) | - | 22.2 (2.6) | - | 22.2 (2.8) | - | 0.74 |
| Father BMI | 24.5 (3.3) | - | 24.6 (3.3) | - | 24.4 (3.3) | - | 0.15 |
| Mother Smoking (cigarettes/day) | |||||||
| 0 | - | 2208 (99.3) | - | 1103 (50.0) | - | 1105 (50.0) | 1.00 |
| ≥1 | - | 15 (0.7) | - | 6 (40.0) | [ | 9 (60.0) | |
| Father Smoking (cigarettes/day) | |||||||
| 0 | - | 1103 (49.6) | - | 555 (50.3) | - | 548 (49.7) | 0.58 |
| <5 | - | 592 (26.6) | - | 278 (47) | - | 314 (53) | |
| 5–10 | - | 308 (13.9) | - | 164 (53.2) | - | 144 (46.8) | |
| >10 | - | 219 (9.9) | - | 117 (53.4) | - | 102 (46.6) | |
| Mother Education, n (%) | |||||||
| Secondary high school or lower | - | 945 (36.7) | - | 507 (53.7) | - | 438 (46.3) | 0.06 |
| High school | - | 657 (25.5) | - | 318 (48.4) | - | 339 (51.6) | |
| Bachelor’s or higher | - | 818 (31.7) | - | 404 (49.4) | - | 414 (50.6) | |
| Father Education, n (%) | |||||||
| Secondary high school or lower | - | 717 (27.8) | - | 370 (51.6) | - | 347 (48.4) | 0.68 |
| High school | - | 812 (31.5) | - | 405 (49.9) | - | 407 (50.1) | |
| Bachelor’s or higher | - | 890 (34.5) | - | 449 (50.4) | - | 441 (49.6) | |
| Household Income (RMB) | |||||||
| <80,000 | - | 594 (25.7) | - | 288 (48.5) | - | 306 (51.5) | 0.28 |
| 80,000–150,000 | - | 924 (39.9) | - | 456 (49.4) | - | 468 (50.6) | |
| >150,000 | - | 795 (34.4) | - | 408 (51.3) | - | 387 (38.7) | |
| Physical Activity (min/day) | 22.9 (27.9) | - | 24.0 (29.7) | - | 21.7 (25.9) | - | 0.04 |
n (%) reported for dichotomous variables; Mean (SD) reported for continuous variables; Boldface indicates statistical significance (p < 0.05); a: Cut off classifications for children and adolescents based on the Working Group for Obesity in China (WGOC) [36]; SD: standard deviation; BMI: body mass index.