BMI by WHO z-scores and NHS/CDC percentiles by weaning group*
| Baby-led group (n=63) | Spoon-fed group (n=63) | |
| WHO z-score† | ||
| −3 | 1 (1.6%) | 0 (0%) |
| −2 | 2 (3.2%) | 0 (0%) |
| −1 | 5 (7.9%) | 3 (4.8%) |
| 0 | 39 (61.9%) | 40 (63.5%) |
| 1 | 15 (23.8%) | 12 (19.0%) |
| 2 | 1 (1.6%) | 8 (12.7%) |
| 3 | 0 (0%) | 0 (0%) |
| NHS percentiles | ||
| Underweight (<2) | 3 (4.7%) | 0 (0%) |
| Healthy weight (2–90) | 51 (81.0%) | 53 (84.1%) |
| Overweight (91–97) | 9 (14.3%) | 2 (3.2%) |
| Obese (98+) | 0 (0%) | 8 (12.7%) |
| CDC percentiles | ||
| Underweight (0–4) | 6 (9.5%) | 1 (1.6%) |
| Healthy weight (5–85) | 49 (77.8%) | 47 (74.6%) |
| Overweight (86–95) | 7 (12.7%) | 8 (12.7%) |
| Obese (96+) | 1 (1.6%) | 7 (11.1%) |
↵* Most participants had a BMI in the average/healthy range across measures.
↵† WHO have suggested a set of cut-offs based on single SD spacing. Thinness: less than −2SD, overweight: between +1SD and less than +2SD, obese: more than +2SD.
BMI, body mass index; CDC, Centers for Disease Control and Prevention; NHS, National Health Service.