Table 2. Odd ratios of obesity according to different levels of indoor and outdoor physical activity, TV watching and sleeping time.
| No. of participants | No. of cases | Odd ratios (95% confidence intervals) | ||
|---|---|---|---|---|
| Model 1* | Model 2† | |||
| Indoor activity categories (hours/day) | ||||
| <5.0 | 407 | 46 | 1.00 | 1.00 |
| 5.0–6.9 | 410 | 46 | 0.98 (0.59–1.64) | 1.01 (0.60–1.69) |
| ≥7.0 | 446 | 36 | 0.76 (0.44–1.32) | 0.82 (0.47–1.42) |
| P for trend | 0.52 | 0.66 | ||
| Indoor activity as a continuous variable (1 hour/day increase) | 0.99 (0.90–1.09) | 0.97 (0.88–1.08) | ||
| Outdoor activity categories (hours/day) | ||||
| <1.5 | 422 | 39 | 1.00 | 1.00 |
| 1.5–1.9 | 322 | 33 | 0.98 (0.58–1.64) | 0.99 (0.59–1.67) |
| ≥2.0 | 519 | 56 | 1.19 (0.75–1.87) | 1.13 (0.71–1.79) |
| P for trend | 0.65 | 0.82 | ||
| Outdoor activity as a continuous variable (1 hour/day increase) | 1.08 (0.88–1.32) | 1.09 (0.87–1.38) | ||
| TV watching time categories (hours/day) | ||||
| 0 | 446 | 32 | 1.00 | 1.00 |
| <1.0 | 453 | 37 | 1.25 (0.74–2.09) | 1.21 (0.72–2.05) |
| ≥1.0 | 364 | 59 | 2.31 (1.41–3.80) | 2.20 (1.33–3.63) |
| P for trend | 0.001 | 0.003 | ||
| TV watching time as a continuous variable (1 hour/day increase) | 1.39 (1.18–1.65) | 1.37 (1.16–1.63) | ||
| Sleeping time categories (hours/day) | ||||
| <11.0 | 469 | 57 | 1.00 | 1.00 |
| 11.0–11.9 | 386 | 38 | 0.97 (0.60–1.56) | 0.99 (0.61–1.59) |
| ≥12.0 | 408 | 33 | 0.71 (0.42–1.18) | 0.75 (0.44–1.26) |
| P for trend | 0.36 | 0.49 | ||
| Sleeping time as a continuous variable (1 hour/day increase) | 0.88 (0.74–1.05) | 0.89 (0.74–1.06) | ||
Obesity was defined as a body mass index more than the 95th percentiles (≥1.645 Z score) for age and gender specific distribution using WHO growth reference.
*Adjusted for maternal age, pre-pregnancy BMI, weight gain during pregnancy, education, occupation, family income, and child age, sex, gestational age, and mode of infant feeding.
†Adjusted for variables in Model 1 and also indoor activity, outdoor activity, TV watching time, and sleeping time, other than the variable in the analyses.