Table 1 Participants’ demographic characteristics

Sample size (n)

16,310 (49.1)

16,903 (50.9)

6733 (50.9)

6504 (49.1)

5385 (48.3)

5772 (51.7)

4192 (47.5)

4627 (52.5)

Age (years)^a

13.3 ± 2.5

13.2 ± 2.5

n.s

10.2 ± 0.8

10.2 ± 0.8

n.s

13.0 ± 0.8

13.0 ± 0.8

n.s

16.2 ± 1.0

16.1 ± 1.0

n.s

Height (cm)^a

151.2 ± 18.3

148.2 ± 14.9

0.27

136.8 ± 10.5

136.6 ± 11.3

0.02

161.7 ± 10.3

158.2 ± 6.9

0.40

173.3 ± 6.7

162.1 ± 5.9

1.31

Weight (kg)^a

46.7 ± 17.8

42.3 ± 13.9

0.34

34.9 ± 10.6

32.5 ± 9.4

0.27

54.2 ± 13.8

49.7 ± 10.2

0.36

65.9 ± 13.8

55.0 ± 12.3

0.86

BMI (kg/m²)^a

19.7 ± 4.2

18.7 ± 3.6

0.26

18.3 ± 3.7

17.1 ± 3.0

0.38

20.5 ± 4.0

19.8 ± 3.5

0.20

21.9 ± 4.2

20.9 ± 3.3

0.26

 Urban

10,490 (66.9)

10,892 (66.6)

n.s

3591 (66.8)

3690 (67.9)

n.s

3790 (67.1)

3964 (67.3)

n.s

2987 (66.8)

3115 (64.3)

0.03

 Rural

5187 (33.1)

5452 (33.4)

1781 (33.2)

1744 (32.1)

1862 (32.9)

1923 (32.7)

1485 (33.2)

1726 (35.7)

 Low

6988 (43.3)

7498 (44.1)

n.s

3122 (46.9)

2994 (45.5)

0.03

2285 (42.9)

2496 (43.0)

n.s

1581 (38.0)

2008 (43.5)

0.06

 Moderate

4357 (27.0)

4451 (26.2)

1856 (27.9)

1759 (26.8)

1382 (26.0)

1511 (26.0)

1119 (26.9)

1181 (25.6)

 High

4793 (29.7)

5047 (29.7)

1683 (25.3)

1822 (27.7)

1654 (31.1)

1798 (31.0)

1456 (31.1)

1427 (30.9)

 Both parents

13,572 (83.2)

13,862 (82.0)

0.02

5498 (81.7)

5148 (79.2)

0.04

4454 (82.7)

4761 (82.5)

n.s

3620 (86.3)

3953 (85.4)

n.s

 One parent

911 (5.6)

954 (5.6)

307 (4.5)

278 (4.3)

345 (6.4)

331 (5.7)

259 (6.2)

345 (7.5)

 Grandparent(s)

1827 (11.2)

2087 (12.4)

928(13.8)

1078 (16.5)

586 (10.9)

680 (11.8)

313 (7.5)

329 (7.1)