Table 1 Descriptive statistics of the study sample stratified by gender (n = 9068)
| Â | Total | Males | Females | |
|---|---|---|---|---|
| Â | Mean (S.D.) | Min-Max | Mean (S.D.) | Mean (S.D.) |
Outcome variable | ||||
 Physical activity | ||||
  Number of days per week engaging in at least one hour of physical activity | 4,2 (2,1) | (0–7) | 4,4 (2,0) | 3,9 (2,1) |
Family SES | ||||
 Low | 730 | 8.1 | 7.1 | 9.0 |
 Middle | 2861 | 31.6 | 28.9 | 34.3 |
 High | 5477 | 60.4 | 64.0 | 56.7 |
Socio-demographic characteristics | ||||
 Gender | ||||
  Males | 4577 | 50.5 | 100.0 |  |
  Females | 4491 | 49.5 |  | 100.0 |
 Age | ||||
   ≤ 13 years | 3321 | 36.6 | 34.8 | 38.5 |
  14 years | 1591 | 17.5 | 18.6 | 16.5 |
  15 years | 2420 | 26.7 | 25.4 | 28.0 |
   ≥ 16 years | 1736 | 19.1 | 21.3 | 17.0 |
 Migration background | ||||
  Non-Western immigrants | 3030 | 33.4 | 33.4 | 33.4 |
  Western immigrants | 677 | 7.5 | 7.8 | 7.1 |
  Native Dutch | 5361 | 59.1 | 58.8 | 59.5 |
 Educational level | ||||
  Basic pre-vocational secondary education | 3017 | 33.1 | 34.2 | 32.3 |
  Theoretical pre-vocational secondary education | 2757 | 30.4 | 29.9 | 30.9 |
  Secondary education | 1541 | 17.0 | 17.0 | 17.0 |
  Pre-university education | 1753 | 19.3 | 18.9 | 19.8 |
 Municipality | ||||
  Rotterdam | 3339 | 36,8 | 36,3 | 37,4 |
  Surrounding municipalities | 5729 | 63,2 | 63,7 | 62,6 |
Behavioural factors | ||||
 Risk of problematic social media use | ||||
  No or very little risk | 7761 | 87.0 | 92.0 | 82.0 |
  High risk | 1156 | 13.0 | 8.0 | 18.0 |
 Risk of problematic gaming | ||||
  No or very little risk | 8299 | 93.3 | 88.4 | 98.2 |
  High risk | 597 | 6.7 | 11.6 | 1.8 |
 Daily smoking | ||||
  No | 8665 | 95.6 | 96.1 | 95.1 |
  Yes | 398 | 4.4 | 3.9 | 4.9 |
 Cannabis use in the last 4 weeks | ||||
  No | 8640 | 95.4 | 94.0 | 96.8 |
  Yes | 417 | 4.6 | 6.0 | 3.2 |
 Binge drinker | ||||
  No | 7652 | 84.4 | 84.3 | 84.6 |
  Yes | 1409 | 15.6 | 15.7 | 15.4 |
 Daily breakfast consumption | ||||
  Yes | 6161 | 68.0 | 72.4 | 63.4 |
  No | 2903 | 32.0 | 27.6 | 36.6 |
 Daily fruit consumption | ||||
  Yes | 2783 | 30.7 | 28.9 | 32.5 |
  No | 6279 | 69.3 | 71.1 | 67.5 |
 Daily vegetable consumption | ||||
  Yes | 3672 | 40.5 | 37.6 | 43.5 |
  No | 5393 | 59.5 | 62.4 | 56.5 |
 Daily water drinking | ||||
  Yes | 5678 | 62.6 | 62.1 | 63.1 |
  No | 3390 | 37.4 | 37.9 | 36.9 |
Psychosocial factors | ||||
 Peer social support | ||||
  High score on social support | 8289 | 92.0 | 90.3 | 93.6 |
  Low score on social support | 725 | 8.0 | 9.7 | 6.4 |
  Self-perceived health | ||||
  Good or very good | 8040 | 88.7 | 91.1 | 86.3 |
  Bad or very bad | 1024 | 11.3 | 8.9 | 13.7 |
Environmental factors | ||||
 Connection with the neighbourhood | ||||
  Strong connection with the neighbourhood | 7878 | 88.6 | 89.2 | 87.9 |
  Weak connection with the neighbourhood | 1018 | 11.4 | 10.8 | 12.1 |