Table 1.
Descriptive statistics for age, physical activity, body image and body mass index, for the whole sample and separately for boys and girls.
| Whole Sample (n = 8042) | Boys (n = 3910) | Girls (n = 4132) | p | |
|---|---|---|---|---|
| Age: Mean (SD) | 13.13 (1.35) | 13.16 (1.35) | 13.11 (1.35) | ˂0.001 a |
| Physical activity: n (%) | ˂0.001 b | |||
| sufficient | 1765 (22.5) | 1116 (29.3) | 649 (16.1) | |
| not sufficient | 6089 (77.5) | 2696 (70.7) | 3393 (83.9) | |
| Body image: n (%) | ˂0.001 b | |||
| fat | 1901 (23.9) | 766 (19.9) | 1135 (27.6) | |
| not fat | 6059 (76.1) | 3083 (80.1) | 2976 (72.4) | |
| BMI: Mean (SD) | 19.34 (3.19) | 19.75 (3.33) | 18.96 (2.99) | ˂0.001 a |
Notes: Number of missing cases per variable: Age—0; physical activity—188; body image—82; BMI—822; BMI, Body mass index; SD, standard deviation; a t-test; b Chi-square test.