Table 3 Handgrip strength levels (kg) according to quintiles of dietary protein and amino acids¹⁾

Total protein

Median (range)

10.3 (1.4–11.5)

12.5 (11.5–13.4)

14.3 (13.4–15.3)

16.5 (15.3–18.0)

20.7 (18.0-62.7)

Model 1²⁾

33.0 ± 0.2

33.2 ± 0.2

33.1 ± 0.2

33.2 ± 0.1

33.4 ± 0.2

0.0614

0.0067

0.04

0.01

0.0030

Model 2³⁾

33.5 ± 0.2

33.7 ± 0.2

33.6 ± 0.2

33.7 ± 0.2

33.9 ± 0.2

0.1995

0.0293

0.03

0.01

0.0150

Model 3⁴⁾

33.4 ± 0.2

33.6 ± 0.2

33.6 ± 0.2

33.7 ± 0.2

33.9 ± 0.2

0.0881

0.0084

0.04

0.01

0.0027

Animal protein

Median (range)

1.9 (0.0-3.3)

4.5 (3.3–5.5)

6.7 (5.5–7.9)

9.3 (7.9–11.1)

14.3 (11.1–60.3)

Model 1

33.1 ± 0.2

33.3 ± 0.2

33.0 ± 0.2

33.2 ± 0.2

33.3 ± 0.2

0.2670

0.2772

0.02

0.01

0.0796

Model 2

33.6 ± 0.2

33.8 ± 0.2

33.5 ± 0.2

33.7 ± 0.2

33.7 ± 0.2

0.3639

0.5309

0.01

0.01

0.2294

Model 3

33.6 ± 0.2

33.7 ± 0.2

33.5 ± 0.2

33.7 ± 0.2

33.8 ± 0.2

0.3064

0.3755

0.02

0.01

0.1020

Plant protein

Median (range)

4.9 (0.1–5.7)

6.3 (5.7–6.8)

7.3 (6.8–7.9)

8.4 (7.9–9.1)

10.2 (9.1–24.1)

Model 1

32.9 ± 0.2

33.1 ± 0.2

33.3 ± 0.2

33.3 ± 0.2

33.3 ± 0.2

0.0561

0.0131

0.06

0.03

0.0359

Model 2

33.3 ± 0.2

33.6 ± 0.2

33.8 ± 0.2*

33.8 ± 0.2*

33.8 ± 0.2

0.0329

0.0085

0.06

0.03

0.0215

Model 3

33.3 ± 0.2

33.6 ± 0.2

33.8 ± 0.2*

33.8 ± 0.2*

33.8 ± 0.2

0.0198

0.0064

0.07

0.03

0.0178

Total (n = 18,565)

Quintile of dietary amino acid intake (g/day)⁵⁾

Per 1 g increase⁶⁾

Quintile 1

(n = 3,713)

Quintile 2

(n = 3,713)

Quintile 3

(n = 3,713)

Quintile 4

(n = 3,713)

Quintile 5

(n = 3,713)

Pvalue

Pfor trend

β

SE

Pvalue

EAAs

Median (range)

15.3 (0.3–17.7)

19.6 (17.7–21.3)

23.1 (21.3–24.9)

27.1 (24.9–30.0)

34.9 (30.0-260.9)

Model 1

33.1 ± 0.2

33.1 ± 0.2

33.1 ± 0.2

33.2 ± 0.2

33.4 ± 0.2

0.2950

0.0297

0.011

0.006

0.0642

Model 2

33.6 ± 0.2

33.6 ± 0.2

33.6 ± 0.2

33.6 ± 0.2

33.8 ± 0.2

0.5824

0.0999

0.007

0.006

0.2009

Model 3

33.5 ± 0.2

33.6 ± 0.2

33.6 ± 0.2

33.7 ± 0.2

33.9 ± 0.2

0.3834

0.0460

0.010

0.007

0.1162

BCAAs

Median (range)

7.7 (0.1–8.9)

9.7 (8.9–10.5)

11.2 (10.5–12.0)

12.8 (12.0–14.0)

16.0 (14.0-123.7)

Model 1

33.2 ± 0.2

32.9 ± 0.2

33.2 ± 0.2

33.2 ± 0.2

33.3 ± 0.2

0.2431

0.2154

0.020

0.014

0.1468

Model 2

33.7 ± 0.2

33.4 ± 0.2

33.7 ± 0.2

33.7 ± 0.2

33.7 ± 0.2

0.3755

0.4302

0.013

0.013

0.3476

Model 3

33.7 ± 0.2

33.4 ± 0.2

33.7 ± 0.2

33.7 ± 0.2

33.7 ± 0.2

0.3386

0.3373

0.017

0.015

0.2586

NEAAs

Median (range)

24.2 (0.6–27.7)

30.4 (27.8–32.8)

35.2 (32.8–37.6)

40.4 (37.6–44.1)

50.5 (44.1-331.4)

Model 1

32.9 ± 0.2

33.2 ± 0.2

33.2 ± 0.2

33.3 ± 0.2

33.4 ± 0.2

0.1317

0.0153

0.008

0.004

0.0493

Model 2

33.4 ± 0.2

33.7 ± 0.2

33.7 ± 0.2

33.7 ± 0.2

33.8 ± 0.2

0.3114

0.0641

0.006

0.004

0.1466

Model 3

33.4 ± 0.2

33.6 ± 0.2

33.7 ± 0.2

33.8 ± 0.2

33.8 ± 0.2

0.2055

0.0316

0.008

0.005

0.0892

EAAs/Total protein

Median (range)

0.28 (0.04–0.30)

0.32 (0.30–0.33)

0.34 (0.33–0.35)

0.36 (0.35–0.37)

0.39 (0.37–2.30)

Model 1

33.3 ± 0.2

33.1 ± 0.2

33.3 ± 0.2

33.2 ± 0.2

33.0 ± 0.2

0.3235

0.0767

-0.124

0.082

0.1303

Model 2

33.8 ± 0.2

33.6 ± 0.2

33.8 ± 0.2

33.6 ± 0.2

33.5 ± 0.2

0.3218

0.0936

-0.122

0.082

0.1359

Model 3

33.8 ± 0.2

33.6 ± 0.2

33.8 ± 0.2

33.6 ± 0.2

33.5 ± 0.2

0.2329

0.0931

-0.123

0.083

0.1388