Table 1 Demographic characteristics of study participants

Total

50,451

25,747

51

24,704

49.0

Eating show

 Low (≤ 3 times/month or none)

28,940

16,133

62.7

12,807

51.8

 High (≥ 1 times/week)

21,511

9,614

37.3

11,897

48.2

Grade

 7—9

27,308

13,852

53.8

13,456

54.5

 10—12

23,143

11,895

46.2

11,248

45.5

Region

 Urban

21,669

11,020

42.8

10,649

43.1

 Suburban

25,106

12,764

49.6

12,342

50.0

 Rural

3,676

1,963

7.6

1,713

6.9

Household economic level

 High

21,345

11,544

44.8

9,801

39.7

 Middle

23,573

11,464

44.5

12,109

49.0

 Low

5,533

2,739

10.6

2,794

11.3

School performance

 High

19,626

10,225

39.7

9,401

38.1

 Middle

15,159

7,460

29.0

7,699

31.2

 Low

15,666

8,062

31.3

7,604

30.8

Living type

 with parents

47,986

24,285

94.3

23,701

95.9

 Others

2,465

1,462

5.7

1,003

4.1

Smoking

 No

48,341

24,263

94.2

24,078

97.5

 Yes

2,110

1,484

5.8

626

2.5

Current alcohol use

 No

44,055

21,980

85.4

22,075

89.4

 Yes

6,396

3,767

14.6

2,629

10.6

Physical activity

 None

16,666

6,485

25.2

10,181

41.2

 1—3 days

21,540

10,631

41.3

10,909

44.2

 4—6 days

8,802

6,010

23.3

2,792

11.3

 7 days

3,443

2,621

10.2

822

3.3

Stress recognition level

 High

20,696

9,128

35.5

11,568

46.8

 Middle

21,189

11,268

43.8

9,921

40.2

 Low

8,566

5,351

20.8

3,215

13.0

BMI^a

 Obesity

6,332

4,096

15.9

2,236

9.1

 Overweight

4,745

2,779

10.8

1,966

8.0

 Normal

35,019

16,945

65.8

18,074

73.2

 Underweight

4,355

1,927

7.5

2,428

9.8