Table 2 Comparison between body mass index and potential overweight/obesity influencing factors of participants (categorical variables)
Variables |  | Underweight/normal n (%) | Overweight/obese n (%) | χ2 (p) |
|---|---|---|---|---|
Sex | Male | 2347 (62.9) | 1385 (37.1) | 290.83*** |
Female | 3042 (80.6) | 732 (19.4) | ||
Educational stage | Primary school | 3025 (70.3) | 1275 (29.7) | 11.62** |
Middle school | 628 (75.2) | 207 (24.8) | ||
High school | 1736 (73.2) | 635 (26.8) | ||
Indoor PA time (m/day)†| < 30 | 2948 (71.7) | 1163 (28.3) | 0.14 |
|  | 30–60 | 1527 (72.1) | 592 (27.9) |  |
|  | > 60 | 856 (71.5) | 341 (28.5) |  |
Outdoor PA time (m/day) | < 30 | 1185 (71.7) | 467 (28.3) | 0.05 |
|  | 30–60 | 2211 (71.9) | 863 (28.1) |  |
|  | > 60 | 1976 (71.7) | 781 (28.3) |  |
Sedentary time (h/day) | < 2 | 768 (69.7) | 334 (30.3) | 18.06** |
|  | 2–4 | 1188 (72.0) | 461 (28.0) |  |
|  | 4–6 | 1120 (70.4) | 472 (29.6) |  |
|  | 6–8 | 1093 (76.1) | 344 (23.9) |  |
|  | > 8 | 1193 (70.7) | 495 (29.3) |  |
Mental healtha | Poor | 1126 (71.3) | 454 (28.7) | 0.35 |
| Â | Good | 4212 (72.0) | 1636 (28.0) | Â |