TABLE 1.
Descriptive characteristics of the study population1
| Characteristics | Total (n = 398) | Boys (n = 202) | Girls (n = 196) | P-sex difference |
|---|---|---|---|---|
| Age (y) | 4.10 (0.08)2 | 4.11 (0.08) | 4.10 (0.08) | 0.028 |
| Maternal ethnicity (% white) | 96.9 | 97.5 | 96.9 | 0.72 |
| Maternal education (%) | ||||
| Low | 7.83 | 6.9 | 8.6 | |
| Moderate | 59.6 | 57.9 | 61.2 | |
| High | 32.7 | 35.2 | 30.1 | 0.51 |
| Maternal BMI (kg/m2) | 24.3 (5.4) | 24.3 (4.9) | 24.0 (5.8) | 0.62 |
| Smoked during pregnancy (%) | 9.3 | 8.9 | 9.7 | 0.86 |
| Birth weight (kg) | 3.5 ± 0.54 | 3.6 ± 0.5 | 3.5 ± 0.5 | 0.054 |
| Breastfeeding (wk) | 13.0 (29.4) | 13.0 (25.9) | 13.0 (31.3) | 0.30 |
| Height (m) | 1.04 ± 0.04 | 1.05 ± 0.04 | 1.04 ± 0.04 | 0.21 |
| Weight (kg) | 17.8 (2.7) | 17.7 (2.8) | 17.8 (2.7) | 0.64 |
| BMI (kg/m2) | 16.3 (1.6) | 16.4 (1.6) | 16.3 (1.6) | 0.82 |
| Percentage of body fat | 26.8 ± 4.9 | 24.2 ± 3.7 | 29.5 ± 4.5 | <0.001 |
| Fat mass (kg) | 4.6 (1.4) | 4.2 (1.1) | 5.2 (1.5) | <0.001 |
| Fat mass index (kg/m2) | 4.2 (1.3) | 3.9 (0.9) | 4.7 (1.3) | <0.001 |
| Trunk fat mass (kg) | 1.6 (0.6) | 1.5 (0.5) | 1.8 (0.7) | <0.001 |
| Trunk fat mass index (kg/m2) | 1.5 (0.6) | 1.3 (0.4) | 1.7 (0.7) | <0.001 |
| Lean mass (kg) | 12.6 ± 1.5 | 13.1 ± 1.4 | 12.1 ± 1.4 | <0.001 |
| Lean mass index (kg/m2.5) | 11.2 ± 0.87 | 11.6 ± 0.81 | 10.8 ± 0.73 | <0.001 |
| Weight status (%)5 | ||||
| Normal | 79.9 | 82.7 | 77.0 | |
| Overweight | 15.6 | 13.9 | 17.4 | |
| Obese | 4.5 | 3.5 | 5.6 | 0.34 |
| LPA (min/d) | 423.6 ± 63.0 | 428.6 ± 64.8 | 418.5 ± 60.8 | 0.11 |
| MPA (min/d) | 58.6 (28.2) | 61.8 (33.3) | 56.8 (23.2) | 0.0073 |
| VPA (min/d) | 23.6 (21.3) | 24.8 (22.9) | 22.9 (19.7) | 0.48 |
| MVPA (min/d) | 84.7 (46.4) | 89.0 (53.8) | 82.3 (39.3) | 0.042 |
| Sedentary time (min/d) | 329.3 ± 72.7 | 327.1 ± 77.5 | 331.6 ± 67.5 | 0.54 |
| Sleep duration (min/d) | 598.2 ± 38.2 | 591.4 ± 39.9 | 605.2 ± 35.7 | 0.0003 |
1
LPA, light physical activity; MPA, moderate physical activity; MVPA, moderate-to-vigorous physical activity; VPA, vigorous physical activity.
2
Median; IQR in parentheses (all such values). Median (IQR) and sex comparisons were made by using Wilcoxon’s rank sum tests.
3
Sex comparisons were made by using chi-square tests for categorical variables.
4
Mean ± SD (all such values). Mean ± SD and sex comparisons were made by using ANOVA.
5
On the basis of International Obesity Task Force age- and sex-specific weight-for-height growth charts.