Table 1 Age-adjusted anthropometric, nutrient intake, and biochemical parameters from 2008 to 2013

Age (years)

49.1 ± 0.2

49.1 ± 0.2

49.3 ± 0.2

50.9 ± 0.2

51.4 ± 0.2

49.2 ± 0.2

<0.001

Male (%)

41.7

43.5

43.2

42.6

41.8

43.1

0.201

Income (Quartile)

<0.001

0.38

 Q1 _lowest

16.0

16.9

17.5

15.5

13.8

15.4

 Q2 _{medium-lowest}

26.6

22.6

26.7

28.2

26.5

25.8

 Q3 _{Medium highest}

27.9

29.5

29.8

29.7

29.1

28.3

 Q4 _highest

29.5

31.0

26.0

26.6

30.6

30.5

Education

<0.001

<0.001

 Elementary school

19.6

18.9

18.6

18.0

17.6

15.9

 Middle school

11.1

10.4

10.2

10.7

9.0

9.1

 High school

39.2

40.4

36.8

37.3

40.6

38.6

 College and over

30.1

30.3

34.4

34.0

32.8

36.4

Smoking (%)^a

25.7 ± 0.7

25.8 ± 0.7

25.2 ± 0.9

24.9 ± 0.9

23.6 ± 0.9

23.2 ± 0.9

0.006

<0.01

Alcohol drinking (%)^a

11.5 ± 0.5

12.14 ± 0.47

10.9 ± 0.5

10.3 ± 0.6

9.94 ± 0.5

9.9 ± 0.6

0.001

0.47

Physical activity (%)

56.7

56.17

50.2

46.4

46.0

45.5

<0.001

<0.001

 High (%)^a

17.4 ± 0.7

18.1 ± 0.7

16.2 ± 0.7

13.9 ± 0.6

14.3 ± 0.8

18.2 ± 0.7

<0.001

0.12

 Moderate (%)^a

14.2 ± 0.8

14.0 ± 0.7

10.8 ± 0.8

9.2 ± 0.6

6.5 ± 0.50

6.4 ± 0.5

<0.001

<0.001

 Walking (%)^a

46.9 ± 0.1

45.5 ± 0.8

40.2 ± 0.9

38.0 ± 0.9

39.9 ± 0.1

37.4 ± 1.0

<0.001

<0.001

Obesity, BMI ≥ 25 (%)

31.6 ± 0.8

31.9 ± 0.8

31.6 ± 0.9

32.5 ± 1.0

32.0 ± 1.0

33.2 ± 0.8

0.57

0.15

Energy intake (kcal)^a

1902.3 ± 16.6

1928.0 ± 12.8

2068.1 ± 17.1

2053.5 ± 18.1

2003.3 ± 18.3

2057.9 ± 15.0

<0.001

<0.001

Carbohydrate (g/dL)^a

308.2 ± 2.6

311.6 ± 2.3

332.8 ± 3.0

325.0 ± 2.7

318.4 ± 3.1

320.0 ± 2.6

<0.001

<0.001

Fat (g/dL)^a

37.5 ± 0.6

39.3 ± 0.5

43.6 ± 0.6

44.0 ± 0.8

44.9 ± 0.8

47.2 ± 0.9

<0.001

<0.001

Fiber (g/dL)^a

7.5 ± 0.1

7.6 ± 0.1

7.8 ± 0.1

7.4 ± 0.1

7.5 ± 0.1

7.8 ± 0.1

0.006

0.42

Protein (g/dL)^a

68.2 ± 0.8

69.8 ± 0.7

76.4 ± 0.8

75.5 ± 1.0

74.4 ± 0.9

75.6 ± 0.9

<0.001

<0.001

Vitamin C (mg/dL)^a

105.8 ± 2.2

106.2 ± 1.9

112.3 ± 2.2

108.8 ± 2.1

112.2 ± 2.8

99.8 ± 2.9

<0.001

0.55

Calcium (mg/dL)^a

493.9 ± 6.3

500.0 ± 6.2

537.0 ± 6.9

520.5 ± 6.8

509.0 ± 7.7

513.3 ± 6.8

<0.001

0.04

Sodium (mg/dL)^a

4970.1 ± 62.1

5060.4 ± 55.6

5249.0 ± 67.8

5179.7 ± 75.1

4860.7 ± 71.5

4314.6 ± 59.1

<0.001

<0.001

Serum vitamin D (ng/mL)^a

19.4 ± 0.3

17.8 ± 0.2

18.0 ± 0.3

17.3 ± 0.2

16.8 ± 0.2

17.2 ± 0.3

<0.001

<0.001