Table 1 Characteristics sample for different cohorts.

N

9764

7119

5468

HAZ M (SD)

− 0.61

(3.2)

− 0.23

(2.9)

0.43

(4.3)

BAZ M (SD)

− 0.12

(2.9)

0.21

(3.5)

0.45

(4.7)

Educational level [N (%)]

 Low

4815

(50.54)

2457

(38.13)

1023

(21.74)

 High

4713

(49.46)

3987

(61.87)

3682

(78.26)

Household income per capita*

 Median

1254.20

3360

5100

 Range (P₂₅–P₇₅)

180–5600

264–17,600

227–31,666

Sex [N (%)]

 Boy

5271

(53.98)

3760

(52.82)

2975

(54.51)

 Girl

4493

(46.02)

3359

(47.18)

2493

(45.59)

Urban–rural area [N (%)]

 Live in rural

7062

(72.33)

5201

(73.06)

3990

(72.97)

 Live in urban

2702

(27.67)

1918

(26.94)

1478

(27.03)

Nationality [N (%)]

 Ethnic minority

1328

(13.74)

1094

(15.41)

815

(14.97)

 Han nationality

8337

(86.26)

6003

(84.57)

4631

(85.03)

Regional [N (%)]

 Central-western

6535

(66.93)

4512

(63.38)

3640

(66.57)

 Eastern

3229

(33.07)

2607

(36.62)

1828

(33.43)

Urbanization index

 Median

45.00

52.30

60.32

 Range (P₂₅–P₇₅)

18.01–83.83

25.35–98.89

30.42–98.55

Environment sanitation score M (SD)

1.1

(1.7)

1.8

(1.3)

2.4

(1.1)

No sister or brother [N (%)]

5041

(51.63)

4862

(68.30)

5118

(93.60)

Have sister or brother [N (%)]

4723

(48.37)

2257

(31.70)

350

(6.40)

Carbohydrate intake percentage M (SD)

66.45

(0.34)

60.45

(0.37)

58.42

(0.37)

Fat intake percentage M (SD)

22.03

(0.67)

27.73

(0.68)

29.18

(0.65)

Protein intake percentage M (SD)

12.06

(0.34)

12.16

(0.38)

12.27

(0.39)

Mother’s BMI (kg/m²) M (SD)

22.21

(2.76)

22.77

(3.51)

22.84

(3.07)

Father’s BMI (kg/m²) M (SD)

22

(2.55)

22.77

(2.88)

23.11

(3.12)

Mother’s height (m) M (SD)

1.57

(0.07)

1.59

(0.06)

1.60

(0.05)

Father’s height (m) M (SD)

1.70

(0.05)

1.71

(0.04)

1.73

(0.06)

Age (years) M (SD)

11.59

(3.38)

11.61

(3.49)

10.99

(3.32)