Table 1.
Anthropometric characteristics of Y13/EA and Y15/MA boys’ vs. girls in rural and urban participants (means and CIs where appropriate).
| Site | Rural (Agincourt) | p-Value (Boys’ vs. Girls within Same Centre) | Urban (Soweto) | p-Value (Boys’ vs. Girls within Same Centre Across Centres) | p-Value (Boys’ vs. Boys Across Centres) | p-Value (Girls’ vs. Girls Across Centres) | ||
|---|---|---|---|---|---|---|---|---|
| Age Group | Y13/EA | Y13/EA | ||||||
| Gender | Boys (n = 105) | Girls (n = 98) | Boys (n = 760) | Girls (n = 805) | ||||
| BMI (kg/m2) (mean 95 CI) | 16.82 | 18.22 | <0.001 | 18.64 | 20.64 | <0.001 | <0.001 | <0.001 |
| (16.41–17.22) | (17.48–18.95) | (18.38–18.90) | (20.31–20.97) | |||||
| Underweight (%) | 4.76 | 8.16 | 0.14 * | 5.39 | 3.73 | <0.001 * | <0.001 | <0.001 |
| Normal (%) | 85.71 | 74.49 | 66.71 | 60.12 | ||||
| Overweight (%) | 3.81 | 11.22 | 6.05 | 15.03 | ||||
| Obese (%) | 5.71 | 6.12 | 21.84 | 21.12 | ||||
| Height (cm) (mean 95 CI) | 144.94 | 148.83 | 0.00 | 154.59 | 155.6 | 0.13 | <0.001 | <0.001 |
| (143.40–146.51) | (147.24–150.41) | (153.94–155.24) | (155.13–156.06) | |||||
| Weight (kg) (mean 95 CI) | 35.62 | 40.72 | 0.00 | 44.87 | 50.16 | <0.001 | <0.001 | <0.001 |
| (34.23–37.01) | (38.60–42.84) | (44.05–45.48) | (49.28–51.04) | |||||
| Age Group | Y15/MA | Y15/MA | ||||||
| Gender | Boys (n = 89) | Girls (n = 100) | Boys (n = 747) | Girls (n = 786) | ||||
| BMI (kg/m2) (mean 95 CI) | 18.9 | 21.43 | 0 | 19.62 | 22.27 | <0.001 | 0.04 | 0.08 |
| (18.39–19.41) | (20.63–22.23) | (19.39–19.85) | (21.95–22.59) | |||||
| Underweight (%) | 4.4 | 3.88 | 0.00 ** | 7.44 | 2.11 | <0.001 * | 0.11 | 0.20 |
| Normal (%) | 90.11 | 73.79 | 79.74 | 69.39 | ||||
| Overweight (%) | 1.1 | 16.5 | 5.51 | 16.98 | ||||
| Obese (%) | 4.4 | 5.83 | 7.31 | 11.52 | ||||
| Height (cm) (mean 95 CI) | 162.55 | 159.87 | 0.01 | 165.91 | 158.66 | <0.001 | <0.001 | 0.06 |
| (160.73–164.38) | (158.79–160.95) | (165.35–166.48) | (158.23–159.09) | |||||
| Weight (kg) (mean 95 CI) | 50.38 | 54.82 | 0.00 | 54.21 | 56.09 | <0.001 | <0.001 | 0.32 |
WHO BMI-for-age Z-score classifications: Underweight = Z ≤ −2SD; Normal = Z > −2 ≤ +1SD; Overweight = Z > +1 ≤ +2SD Obese = Z > +2SD. Y13/EA = year 13/early-adolescents; Y15/MA = year 15/mid-adolescents; BMI = body mass index (kg/m2), Kg = kilogram; cm = centimetres; p-value based on Pearson Chi-squared test for categorical and t independent test for continuous variables * p-value based on Pearson Chi-squared test; ** p-value based on both Pearson Chi-squared and Fisher exact test. Significant differences set at p < 0.05.