Age, ethnicity and socioeconomic status of the sample by sex
| Boys | Girls | |
|---|---|---|
| Total sample (n) | 2577 | 1742 |
| Mean (SD) age (years) | 11.81 (0.36) | 11.84 (0.32) |
| Mean (SD) body mass index (kg/m2) | 19.03 (3.37) | 19.98 (3.82) |
| Ethnic group, n (%) | ||
| White | 1597 (65.7) | 1010 (61.6) |
| Black and mixed black | 582 (23.9) | 454 (27.7) |
| Asian and mixed Asian | 253 (10.4) | 175 (10.7) |
| Townsend Index (Mean (SD)) | ||
| Higher | 877 (34.4) | 555 (32.1) |
| Intermediate | 775 (30.4) | 462 (26.8) |
| Lower | 898 (35.2) | 710 (41.1) |