TABLE 1.

Combinations of metabolites accurately identify the type of diet being consumed¹

Classifier	Accuracy, %	Misclassifications	Metabolites most strongly contributing to classifier
3-way (LF vs. LGI vs. VLC)	95	LF misclassified as LGI (1), LGI misclassified as LF (1), VLC misclassified as LF (1)	4-pyridoxate, C2 carnitine, C34:4 PC, C5 carnitine, C50:4 TAG, C52:5 TAG, C54:4 TAG, C56:9 TAG, C58:9 TAG, GABA, allantoin, cytidine, cytosine, gentisate, hippurate, indole-3-propionate, indoxylsulfate, pipecolic acid, sorbitol, thiamin, threonine, valine
LF vs. LGI	95	LF misclassified as LGI (2)	11-HETE, 4-pyridoxate, C36:4 DAG, C42:0 TAG, C50:4 TAG, C56:9 TAG, GABA, alanine, allantoin, cytidine, cytosine, hippurate, hydroxyproline, thiamin
LF vs. VLC	98	VLC misclassified as LF (1)	4-pyridoxate, C34:3 PC, C34:4 PC, C5 carnitine, C52:5 TAG, C52:6 TAG, C54:5 TAG, C54:8 TAG, C56:10 TAG, C9 carnitine, GABA, allantoin, aminoisobutyric acid, β-hydroxybutyrate, gentisate, indole-3-propionate, indoxylsulfate, leucine, propionate, sorbitol, thiamin, threonine, uracil
LGI vs. VLC	100	None	C18:2 LPE, C2 carnitine, C20:4 CE, C34:0 PC, C34:4 PC, C48:3 TAG, C5 carnitine, C54:4 TAG, C5:1 carnitine, C60:12 TAG, β-alanine, creatine, cytosine, hippurate, indole-3-propionate, indoxylsulfate, pipecolic acid, sorbitol

¹ Metabolites shown are those that most strongly contributed to the classifier for the comparison shown in the left-hand column. GABA, γ-aminobutyric acid; LF, low-fat diet; LGI, low–glycemic index diet; TAG, triacylglycerol; VLC, very–low carbohydrate diet.