Table 2.
Gender differences in body composition and weight status categories, by birth cohort
| Birth cohort | ||||||
|---|---|---|---|---|---|---|
| 1999-2000 (n = 1158) | 2007-2008 (n = 1588) | |||||
| Boys | Girls | Boys | Girls | |||
| n = 587 | n = 571 | p | n = 806 | n = 782 | p | |
| Body composition variables, mean (SD) | ||||||
| BMI (kg/m2) | 19.2 (3.8) | 18.8 (3.5) | 0.1 | 16.0 (2.5) | 15.8 (2.5) | 0.2 |
| BF% | 23.9 (7.1) | 26.8 (6.1) | <0.001 | 20.0 (5.2) | 20.4 (6.4) | 0.2 |
| BMI-for-age z-score | 0.9 (1.4) | 0.7 (1.3) | 0.002 | 0.2 (1.4) | 0.1 (1.4) | 0.1 |
| Weight status categories, % (95 % CI) | ||||||
| Underweight | 8.5 (6.2-10.9) | 7.7 (5.4-10.0) | 0.69 | 19.9 (17.0-22.7) | 21.2 (18.3-24.1) | 0.54 |
| Normal weight | 53.8 (49.7-57.9) | 59.0 (54.9-63.1) | 0.08 | 61.4 (58.0-64.8) | 56.5 (52.9-60.1) | 0.05 |
| Overweight | 27.1 (23.4-30.8) | 23.8 (20.2-27.4) | 0.23 | 10.3 (8.1-12.4) | 13.4 (11.0-15.9) | 0.06 |
| Obesity | 10.6 (7.9-13.1) | 9.5 (7.0-11.9) | 0.60 | 8.4 (6.4-10.4) | 8.8 (6.8-10.9) | 0.85 |
| Overweight/ obesity | 37.7 (33.6-41.6) | 33.3 (29.3-37.2) | 0.13 | 18.7 (16.0-21.3) | 22.2 (19.3-25.2) | 0.09 |
Abbreviations: BMI body mass index, BF% body fat percentage, CI confidence interval, SD Standard deviation; in bold when p < 0.05