Table 3.

Cross-validated R² using metabolite data alone on predicting dietary intakes of energy, protein, carbohydrate and fat.

	Energy (kcal/d)
	Serum	24-hour Urine	Serum + 24-hour Urine	Spot Urine	Serum + Spot Urine	Serum	24-hour Urine	Serum + 24-hour Urine	Spot Urine	Serum + Spot Urine
Model 1a	12.8%	1.4%	12.0%	0.4%	10.1%
Model 2b	11.6%	0.8%	11.2%	0.7%	10.7%
Model 3c	55.1%	53.3%	55.0%	53.8%	55.5%
	Protein (g/d)					Protein (%E)
	Serum	24-hour Urine	Serum + 24-hour Urine	Spot Urine	Serum + Spot Urine	Serum	24-hour Urine	Serum + 24-hour Urine	Spot Urine	Serum + Spot Urine
Model 1	23.8%	17.1%	24.0%	5.5%	20.4%	30.5%	36.0%	36.3%	19.8%	28.3%
Model 2	27.4%	24.8%	26.5%	7.5%	24.9%	28.8%	36.6%	33.9%	18.4%	27.0%
Model 3	48.1%	47.8%	47.7%	49.3%	52.0%	34.9%	45.0%	40.9%	32.8%	34.8%
	Carbohydrate (g/d)					Carbohydrate (%E)
	Serum	24-hour Urine	Serum + 24-hour Urine	Spot Urine	Serum + Spot Urine	Serum	24-hour Urine	Serum + 24-hour Urine	Spot Urine	Serum + Spot Urine
Model 1	34.2%	6.3%	33.5%	1.4%	36.1%	32.8%	22.8%	37.1%	2.1%	30.4%
Model 2	33.7%	5.2%	33.0%	1.2%	35.7%	32.2%	22.6%	36.2%	2.4%	29.9%
Model 3	55.6%	40.4%	55.9%	34.2%	57.0%	33.8%	26.5%	37.0%	5.4%	33.0%
	Fat (g/d)					Fat (%E)
	Serum	24-hour Urine	Serum + 24-hour Urine	Spot Urine	Serum + Spot Urine	Serum	24-hour Urine	Serum + 24-hour Urine	Spot Urine	Serum + Spot Urine
Model 1	2.4%	0.7%	2.4%	1.0%	3.5%	12.6%	0.9%	11.1%	1.6%	13.9%
Model 2	1.8%	0.4%	1.5%	1.1%	2.3%	12.8%	1.2%	11.8%	1.8%	14.4%
Model 3	21.0%	19.9%	20.4%	19.2%	20.9%	10.3%	1.2%	9.1%	1.5%	10.1%

^aModel 1: Metabolites only

^bModel 2: Metabolites + Participant Characteristics

^cModel 3: Metabolites + Participant Characteristics + Diet-related Biomarker (Total Energy Intake, Urine Nitrogen)

^*Serum metabolites were measured by LC-MS/MS and direct-injection MS/MS (lipidomics). 24-hour and spot urinary metabolites were measured by NMR and GC-MS. See text for additional information.