Baseline characteristics of the study sample
| Characteristics | Control | Intervention | Total |
| Cluster level | (n=10) | (n=10) | (n=20) |
| Mean number of participants (range) | 33 (15–47) | 34 (15–61) | 34 (15–61) |
| Mean (range) of students in cluster taking part (%) | 80 (69–100) | 79 (48–100) | 79 (48–100) |
| Individual level | (n=333) | (n=337) | (n=670) |
| Age, mean (SD), years | 16.0 (0.5) | 16.0 (0.4) | 16.0 (0.4) |
| Female participants, n (%) | 130 (39.0) | 169 (50.1) | 299 (44.6) |
| Born in Australia, n (%)* | 291 (87.9) | 296 (88.4) | 587 (88.1) |
| English spoken at home, n (%)* | 308 (93.1) | 310 (92.5) | 618 (92.8) |
| Cultural background, n (%)* Australian European African Asian Middle Eastern Other | 230 (69.5) 28 (8.5 3 (0.9) 18 (5.4) 3 (0.9) 49 (14.8) | 239 (71.3) 39 (11.6) 3 (0.9) 21 (6.3) 4 (1.2) 29 (8.7) | 469 (70.4) 67 (10.1) 6 (0.9) 39 (5.9) 7 (1.1) 78 (11.6) |
| Indigenous decent, n (%)* Yes No | 37 (11.2) 294 (88.8) | 24 (7.2) 311 (92.8) | 61 (9.2) 605 (90.8) |
| Socioeconomic status, n (%)† Low Medium High | 48 (14.5) 170 (51.4) 113 (34.1) | 81 (24.3) 169 (50.8) 83 (24.9) | 129 (19.4) 339 (51.1) 196 (29.5) |
| Weight status, n (%)‡ Underweight Healthy weight Overweight Obese | 16 (4.9) 207 (63.1) 72 (22.0) 33 (10.1) | 10 (3.0) 238 (71.5) 62 (18.6) 23 (6.9) | 26 (3.9) 445 (67.3) 134 (20.3) 56 (8.5) |
*Four participants did not answer the background demographic questions.
†Socioeconomic status determined by population tertile using socioeconomic indexes for areas of relative socioeconomic disadvantage based on residential postcode; six participants did not provide their residential postcode.
‡Nine participants were not measured for height and/or weight.