TABLE 4.

Biomarker model of added sugar intake based on serum amino acid CIRs and participant characteristics in the NPAAS-FS¹

Model terms	β ± SE	P	R 2
Intercept	134 ± 32	<0.0001	0.37
CIR-Ala	8.78 ± 1.22	<0.0001
CIR-Gly	−3.11 ± 0.58	<0.0001
CIR-Ile	−3.19 ± 1.40	0.02
Smoking	21.17 ± 9.13	0.02
Body weight	0.20 ± 0.11	0.09
LPA	−0.16 ± 0.09	0.09

¹Model includes amino acid CIR and participant characteristics that remained significant on the basis of a backward-selection process (P = 0.1). CIR, carbon isotope ratio; LPA, leisure physical activity; NPAAS-FS, Nutrition and Physical Activity Assessment Study Feeding Study (n = 145).