Table 1 Descriptive characteristics of the study subjects

Age (Mean ± SD)

14.5 ± 1.8

14.4 ± 1.9

14.4 ± 1.8

Residence (%)

Urban

39.9

37.9

38.7

Rural

60.1

62.1

61.3

Weight (kg, Mean ± SD)

51.3 ± 10.7

48.6 ± 9.3

50.2 ± 10.2

Height (cm, Mean ± SD)

161.4 ± 9.2

157.3 ± 6.9

159.7 ± 8.6

BMI (kg/m², Mean ± SD)

19.5 ± 2.9

19.5 ± 3.1

19.5 ± 3.0

Weight status (%)*

   Overweight

13.2

11.5

12.5

Urban

27.4

16.8

22.7

Rural

4.6

8.0

6.0

   Normal

83.2

86.0

84.4

Urban

71.8

82.2

76.4

Rural

90.1

88.5

89.4

   Underweight

3.6

2.5

3.1

Urban

0.8

1.0

0.9

Rural

5.3

3.5

4.6

Perceived weight status (%)

   Too thin

7.2

2.7

5.3

Urban

4.4

3.1

3.8

Rural

9.0

2.4

6.3

   Relative thin

34.1

17.3

27.1

Urban

31.3

18.8

27.8

Rural

35.8

16.3

26.0

   All right

44.2

55.1

48.8

Urban

43.7

47.1

51.1

Rural

44.6

60.4

45.1

   Relative heavy

12.9

23.6

17.4

Urban

17.5

29.8

14.0

Rural

10.2

19.4

22.8

   Too heavy

1.5

1.3

1.4

Urban

3.2

1.0

0.9

Rural

0.5

1.4

2.3