Table 1. General characteristics of the study population, separately for girls and boys.
| Girls | n = 732 | Boys | n = 700 | ||
| Mean (sd) | Mean (sd) | ||||
| Age (year) | 12.7 | (0.4) | 12.7 | (0.4) | |
| Weight (kg) | 48.9 | (9.4) | 47.5 | (9.2) | |
| Height (cm) | 160.5 | (7.2) | 159.5 | (8.2) | |
| Waist circumference (cm) | 66.1 | (6.5) | 66.8 | (6.8) | |
| BMI (kg/m2) | 18.9 | (2.7) | 18.6 | (2.6) | |
| Weight z-score | 0.12 | (1.0) | 0.18 | (1.0) | |
| Height z-score | 0.21 | (1.0) | 0.13 | (1.0) | |
| Weight for height z-score | −0.13 | (1.0) | 0.11 | (1.1) | |
| BMI z-score | 0.05 | (1.1) | 0.19 | (1.1) | |
| WC z-score | 0.26 | (0.9) | 0.08 | (1.0) | |
| Birth weight (g) | 3466 | (505) | 3600 | (543) | |
| Systolic blood pressure (mmHg) | 114 | (9.5) | 115 | (8.9) | |
| Diastolic blood pressure (mmHg) | 67 | (6.3) | 67 | (6.6) | |
| Puberty development scale * | 1.8 | (0.6) | 1.3 | (0.3) | |
| Total cholesterol (mmol) | 4.1 | (0.6) | 4.0 | (0.7) | |
| HDL cholesterol (mmol) | 1.4 | (0.3) | 1.4 | (0.3) | |
| Total-to-HDL cholesterol ratio | 3.1 | (0.7) | 3.1 | (0.8) | |
| HbA1c (mmol/mol) | 32 | (2.4) | 32 | (2.2) | |
| n (%) | n (%) | ||||
| Overweight (including obesity) | 80 | (11.0) | 79 | (11.3) | |
| Obesity | 6 | (0.8) | 8 | (1.2) | |
| BMI category 8 and 12 years | |||||
| Normal-normal | 550 | (88.0) | 505 | (87.8) | |
| High-normal | 23 | (3.7) | 13 | (2.3) | |
| Normal-high | 16 | (2.6) | 27 | (4.7) | |
| High-high | 36 | (5.8) | 30 | (5.2) | |
| WC category 8 and 12 years | |||||
| Normal-normal | 538 | (86.1) | 494 | (85.9) | |
| High-normal | 29 | (4.6) | 21 | (3.7) | |
| Normal-high | 24 | (3.8) | 23 | (4.0) | |
| High-high | 34 | (5.4) | 37 | (6.4) | |
| Systolic blood pressure >130 mmHg** | 45 | (6.2) | 36 | (5.2) | |
| Diastolic blood pressure >85 mmHg** | 1 | (0.1) | 3 | (0.4) | |
| HDL cholesterol <1.03 mmol** | 85 | (13.4) | 88 | (13.7) | |
| Maternal overweight before pregnancy | 113 | (15.5) | 122 | (17.5) | |
| Maternal education | |||||
| Low | 122 | (16.8) | 120 | (17.2) | |
| Intermediate | 316 | (43.6) | 276 | (39.6) | |
| High | 287 | (39.6) | 301 | (43.2) | |
| Maternal smoking | 106 | (14.6) | 86 | (12.3) | |
| Allergic mother *** | 243 | (33.4) | 222 | (31.9) | |
| Watching TV | |||||
| ≤1 day/week | 44 | (6.2) | 41 | (6.0) | |
| 2–4 days/week | 103 | (14.4) | 81 | (5.8) | |
| 5–6 days/week | 133 | (18.6) | 116 | (17.1) | |
| daily | 436 | (60.9) | 442 | (65.0) | |
| Computer | |||||
| ≤1 day/week | 98 | (13.7) | 41 | (6.0) | |
| 2–4 days/week | 278 | (38.9) | 195 | (28.7) | |
| 5–6 days/week | 205 | (28.6) | 184 | (27.1) | |
| daily | 135 | (18.9) | 260 | (38.2) | |
| Region **** | |||||
| North | 255 | (35.1) | 204 | (29.3) | |
| West | 305 | (42.0) | 334 | (47.9) | |
| Middle | 167 | (23.0) | 159 | (22.8) | |
*
The PDS ranges from 1 to 5 where a score of 1 indicates that puberty has not started yet and a score of 5 indicates that the puberty development seems complete. [19].
**
The International Diabetes Federation provides thresholds for defining children at risk of future cardiovascular disease for HDL cholesterol and blood pressure. [28].
***
Allergic mother: ≥1 time yes to ‘ever asthma’, ‘allergy to pets’, ‘allergy to house dust mite’, or ‘nose allergy like hay fever’.
****
Regions: North: provinces Groningen, Friesland, Drenthe; West: region of Rotterdam; Middle: provinces Utrecht and Gelderland.