Table 1 Baseline characteristics of the study population by quartiles of dietary insulin load (N = 2198)

Insulin load

137 ± 26

196 ± 14

250 ± 17

359 ± 67

< 0.001

Insulin index

48.6 ± 6.4

50.6 ± 6.2

52.6 ± 5.7

55.0 ± 5.9

< 0.001

Age (years)

39.2 ± 13.4

38.3 ± 13.2

38.7 ± 13.2

37.1 ± 13.5

< 0.05

Male (%)

27.1

36.9

52.8

62.5

< 0.001

Body mass index (kg/m2)

26.8 ± 4.8

26.6 ± 4.6

26.6 ± 4.9

26.3 ± 4.9

NS

Physical activity (MET_h/week)

23.6 (9.3–46.1)

23.4 (10.4–47.8)

24.3(10.4–50.7)

24.8 (10.9–55.5)

< 0.001

Current smoker (%)

9.8

10.9

13.3

14.2

< 0.05

Diabetes and pre-diabetes (%)

12.0

10.5

12.9

8.7

NS

Hypertension (%)

8.1

7.7

9.5

12.6

< 0.01

 Energy (kcal)

1521 ± 396

2019 ± 371

2430 ± 434

3095 ± 529

< 0.001

 Fruit and vegetable (serving/d/1000 Kcal)

3.0 ± 1.6

2.8 ± 1.4

2.6 ± 1.3

2.1 ± 1.1

< 0.001

 Refined grain (serving/d/1000 Kcal)

2.0 ± 1.1

2.1 ± 1.0

2.3 ± 1.1

2.8 ± 15

< 0.001

 Red and processed meat (serving/wk./1000 Kcal)

2.2 (1.3–3.8)

2.3 (1.3–3.7)

2.1 (1.3–3.4)

2.0 (1.1–3.4)

< 0.05

 Nut and legume (serving/wk./1000 Kcal)

0.99 (0.59–1.69)

0.96 (0.57–1.60)

0.97 (0.58–1.65)

0.87 (0.48–1.46)

< 0.05

 Carbohydrate (% of energy)

54.9 ± 7.4

56.3 ± 6.8

57.9 ± 6.3

60.1 ± 6.7

< 0.001

 Fat (% of energy)

33.9 ± 7.4

32.5 ± 6.6

31.1 ± 6.2

28.7 ± 6.3

< 0.001

 Protein (% of energy)

13.8 ± 2.6

13.8 ± 2.3

13.4 ± 2.1

13.3 ± 2.2

< 0.001

 Fiber (g/1000 Kcal)

14.9 ± 5.6

15.6 ± 5.5

16.6 ± 6.9

18.1 ± 8.2

< 0.001