Baseline characteristics of adolescents participating in the Ungdata surveys in 2017, 2018 and 2019
| Variable | Total (%) | 2017 (%) | 2018 (%) | 2019 (%) |
| n | 278 891 | 101 997 | 66 017 | 110 877 |
| School level | ||||
| Lower secondary | 160 352 (57.5) | 61 768 (60.6) | 38 256 (57.9) | 60 328 (54.4) |
| Upper secondary | 118 539 (42.5) | 40 229 (39.4) | 27 761 (42.1) | 50 549 (45.6) |
| Grade | ||||
| 8 | 52 984 (19.0) | 20 381 (20.0) | 12 695 (19.2) | 19 908 (18.0) |
| 9 | 51 393 (18.4) | 19 514 (19.1) | 12 558 (19.0) | 19 321 (17.4) |
| 10 | 50 547 (18.1) | 19 632 (19.2) | 11 687 (17.7) | 19 228 (17.3) |
| 11 | 50 972 (18.3) | 18 580 (18.2) | 11 190 (16.9) | 21 202 (19.1) |
| 12 | 40 391 (14.5) | 12 824 (12.6) | 9360 (14.2) | 18 207 (16.4) |
| 13 | 26 351 (9.5) | 8632 (8.5) | 7091 (10.7) | 10 628 (9.6) |
| Missing | 6253 (2.2) | 2434 (2.4) | 1436 (2.2) | 2383 (2.2) |
| Gender | ||||
| Female | 138 218 (49.6) | 47 218 (46.3) | 31 802 (48.2) | 54 020 (48.7) |
| Male | 133 040 (47.7) | 48 254 (47.3) | 33 908 (51.4) | 56 056 (50.6) |
| Missing | 7633 (2.7) | 6525 (6.4) | 307 (0.5) | 801 (0.7) |
| Residency | ||||
| 1 | 56 012 (20.2) | 14 909 (14.7) | 22 358 (34.0) | 18 745 (16.9) |
| 2 | 63 413 (22.8) | 30 793 (30.5) | 5601 (8.5) | 27 019 (24.4) |
| 3 | 74 853 (26.9) | 23 190 (22.9) | 16 117 (25.5) | 35 546 (32.1) |
| 4 | 46 826 (16.9) | 16 688 (16.5) | 11 286 (17.1) | 18 852 (17.0) |
| 5 | 27 900 (10.0) | 12 358 (12.2) | 7609 (11.6) | 7933 (7.1) |
| 6 | 8847 (3.2) | 3195 (3.2) | 2870 (4.4) | 2782 (2.5) |
| Frequency of physical activity | ||||
| Never | 4518 (1.6) | 1374 (1.3) | 1218 (1.8) | 1926 (1.7) |
| Seldom | 19 642 (7.0) | 6314 (6.2) | 4997 (7.6) | 8331 (7.5) |
| 1–2 times a month | 18 007 (6.5) | 6105 (6.0) | 4709 (7.1) | 7193 (6.5) |
| 1–2 times a week | 75 687 (27.1) | 26 901 (26.4) | 18 484 (28.0) | 30 302 (27.3) |
| 3–4 times a week | 89 537 (32.1) | 33 164 (32.5) | 20 458 (31.0) | 35 915 (32.4) |
| ≥ 5 times a week | 65 897 (23.6) | 25 472 (25.0) | 14 402 (21.8) | 26 023 (23.5) |
| Missing | 5603 (2.0) | 2667 (2.6) | 1749 (2.7) | 1187 (1.1) |
| Leisure screen time | ||||
| No time | 2489 (0.9) | 1015 (1.0) | 630 (1.0) | 844 (0.8) |
| ≤ 1 hour daily | 8261 (3.0) | 3499 (3.4) | 2049 (3.1) | 2713 (2.5) |
| 1–2 hours daily | 32 484 (11.6) | 13 220 (13.0) | 7676 (11.6) | 11 588 (10.4) |
| 2–3 hours daily | 60 567 (21.7) | 22 786 (22.3) | 14 284 (21.6) | 23 497 (21.2) |
| 3–4 hours daily | 75 781 (27.2) | 27 296 (26.8) | 17 654 (26.7) | 30 831 (27.8) |
| 4–6 hours daily | 59 250 (21.2) | 20 379 (20.0) | 13 878 (21.0) | 24 993 (22.5) |
| ≥ 6 hours daily | 36 168 (13.0) | 12 563 (12.3) | 8873 (13.4) | 14 732 (13.3) |
| Missing | 3891 (1.4) | 1239 (1.2) | 973 (1.5) | 1679 (1.5) |
| Energy drink consumption | ||||
| Never | 128 365 (46.0) | 46 782 (45.9) | 31 055 (47.0) | 50 528 (45.6) |
| < Once a week | 71 200 (25.5) | 27 530 (27.0) | 16 594 (25.1) | 27 076 (24.4) |
| Once a week | 29 653 (10.6) | 10 936 (10.7) | 6784 (10.3) | 11 933 (10.8) |
| 2–3 times a week | 28 974 (10.4) | 10 065 (9.9) | 6595 (10.0) | 12 314 (11.1) |
| 4–6 times a week | 12 310 (4.4) | 4038 (4.0) | 2843 (4.3) | 5429 (4.9) |
| Every day | 4080 (1.5) | 1250 (1.2) | 1005 (1.5) | 1825 (1.6) |
| Several times a day | 4309 (1.5) | 1396 (1.4) | 1141 (1.7) | 1772 (1.6) |