Table 1 Characteristics of study participants by quartile of dietary glycemic index in the JPHC Study

Men (n = 27769)

Age,mean (SD)

55.5

(7.8)

56.3

(7.8)

56.6

(7.8)

57.5

(7.7)

Physical activity, metabolic equivalents -h/d, mean (SD)^a

33.2

(6.7)

33.8

(6.7)

34.3

(6.8)

34.5

(6.8)

BMI, mean (SD)^b

23.7

(2.9)

23.6

(2.8)

23.5

(2.8)

23.4

(2.8)

History of hypertension, %

14.3

16.8

18.0

18.7

Current smokers^c, %

51.5

45.2

44.3

44.6

Occupation^d, %

  Agriculture/forestry/fishery

21.6

27.6

31.6

37.4

  Salaried/self-employed/professional

65.0

59.4

54.9

49.9

  Housework/unemployed/retired

13.4

13.0

13.5

12.8

Dietary GI, mean (SD)

55

(4)

61

(1)

64

(1)

68

(2)

Dietary GL, mean (SD)

159

(59)

171

(50)

175

(51)

180

(56)

Total energy, kcal/d, mean (SD)

2460

(876)

2309

(699)

2174

(656)

1991

(626)

Carbohydrate, g/d, mean (SD)

302

(112)

294

(86)

285

(84)

274

(85)

Rice, g/d, mean (SD)

321.4

(154.5)

410.9

(151.7)

470.6

(170.5)

545.7

(199.5)

Rice with millet or barley, g/d, mean (SD)

24.2

(77.7)

26.7

(88.2)

25.2

(91.6)

20.7

(83.3)

Bread, g/d, mean (SD)

27.0

(34.7)

25.2

(36.2)

20.7

(35.7)

17.3

(51.0)

Udon, g/d, mean (SD)

73.9

(109.7)

58.4

(67.5)

45.1

(48.4)

29.1

(33.3)

Magnesium intake, mg/d, mean (SD)

349.4

(146.6)

312.7

(109.1)

277.7

(97.6)

231.6

(84.0)

Calcium, mg/d, mean (SD)

737

(497)

574

(284)

469

(220)

350

(177)

Dietary fiber, g/d, mean (SD)

15

(8)

13

(6)

12

(6)

9

(4)

Total fat, g/d, mean (SD)

75.2

(39.1)

64.4

(29.5)

55.0

(26.4)

42.3

(22.9)

Alcohol, g/week, (SD)

197.5

(241.9)

200.8

(235.8)

214.7

(243.2)

230.8

(249.3)

Coffee intake, almost never^e, %

15.8

22.8

32.1

51.7

Women (n = 36864)

Age,mean (SD)

55.3

(7.6)

56.1

(7.6)

57.2

(7.8)

58.9

(8.0)

Physical activity, metabolic equivalents -h/d, mean (SD)^a

32.8

(5.7)

32.9

(5.7)

32.9

(5.8)

32.7

(5.8)

BMI, mean (SD)^b

23.3

(3.0)

23.4

(3.0)

23.5

(3.1)

23.6

(3.2)

History of hypertension, %

15.1

16.8

19.2

22.9

Current smokers^c, %

6.5

4.4

3.8

4.1

Occupation^d, %

  Agriculture/forestry/fishery

16.2

22.8

27.4

32.2

  Salaried/self-employed/professional

42.5

37.0

32.8

27.8

  Housework/unemployed/retired

41.3

40.2

39.7

40.0

Dietary GI, mean (SD)

54

(3)

59

(1)

62

(1)

67

(2)

Dietary GL, mean (SD)

143

(53)

154

(43)

151

(39)

148

(44)

Total energy, kcal/d, mean (SD)

2215

(793)

2040

(598)

1835

(508)

1565

(509)

Carbohydrate, g/d, mean (SD)

283

(103)

276

(77)

256

(66)

232

(70)

Rice, g/d, mean (SD)

256.4

(126.1)

334.0

(117.8)

371.1

(120.7)

419.4

(142.8)

Rice with millet or barley, g/d, mean (SD)

24.8

(71.2)

27.6

(79.9)

27.1

(81.2)

21.6

(70.7)

Bread, g/d, mean (SD)

32.4

(32.8)

31.9

(39.8)

27.8

(43.5)

24.6

(59.1)

Udon, g/d, mean (SD)

62.5

(89.7)

52.0

(54.3)

41.0

(43.7)

27.1

(31.7)

Magnesium, mg/d, mean (SD)

355.8

(145.7)

312.2

(105.9)

269.8

(86.1)

211.2

(79.0)

Calcium, mg/d, mean (SD)

852

(530)

641

(280)

516

(219)

362

(181)

Dietary fiber, g/d, mean (SD)

18

(9)

16

(7)

13

(6)

10

(5)

Total fat, g/d, mean (SD)

78.5

(37.0)

66.0

(28.9)

55.6

(24.4)

41.8

(23.2)

Alcohol, g/week, (SD)

18.1

(69.0)

14.1

(62.4)

13.2

(63.3)

11.2

(56.8)

Coffee intake, almost never^e, %

13.4

20.8

30.3

47.2