Table 4.
Variables selected for predicting dietary protein intake (E%) with their R2 and corresponding cross-validated R2 (%) using serum + 24-hour urine metabolites without participant characteristics or established diet-related biomarkers (Model 1).
| Variable# | Coefficient | R2 | CV-R2 |
|---|---|---|---|
| Intercept | −2.836 | ||
| Propanediol (urine) | −0.082 | 17.6% | 10.1% |
| Lysophosphatidylethanolamine (LPE 16:0*) (serum) | 0.251 | 17.1% | 9.8% |
| Urea (urine) | 0.138 | 5.7% | 3.3% |
| Arabitol/Xylitol (serum) | −0.101 | 5.3% | 3.1% |
| Creatine (serum) | 0.065 | 4.8% | 2.8% |
| 2-Oxoisovalerate (serum) | 0.125 | 4.2% | 2.4% |
| 2-Hydroxyglutarate (serum) | −0.136 | 3.4% | 1.9% |
| Maltose (urine) | −0.019 | 1.7% | 1.0% |
| Methyl-glycocholate (urine) | −0.046 | 1.4% | 0.8% |
| 2-Hydroxybutyrate (serum) | 0.057 | 0.8% | 0.5% |
| Cholesteryl ester (CE 18:3*) (serum) | −0.075 | 0.6% | 0.4% |
| Glutamine (serum) | −0.111 | 0.3% | 0.2% |
| Uridine (serum) | 0.052 | 0.2% | 0.1% |
| Cholesteryl ester (CE 22:6*) (serum) | 0.020 | 0.1% | 0.0% |
| Creatine (urine) | −0.001 | 0.0% | 0.0% |
| Total | 63.2% | 36.3% |
#
Reordered by R2
*
In LPE 16:0, 16 indicates number of carbons and 0 indicates number of double bonds in the fatty acid chain.
LPE: lysophosphatidylethanolamine. CE: cholesterol ester.