TABLE 4.

Linear models of dietary intake of the postmenopausal women in the NPAAS-FS included in this study, based on single isotopes, multiple isotopes, and final models with participant characteristics¹

Dietary intake	Model type	Model variables	ß ± SE	P	R 2
Fish/seafood	Single isotope	NIR	33.42 ± 3.56	<0.01	0.38
	Multiple isotope	NIR	33.10 ± 3.80	<0.01	0.38
		CIR	−1.45 ± 3.13	0.64
		SIR	1.58 ± 1.83	0.39
	Final model2	NIR	32.90 ± 3.52	<0.01	0.40
		Ethnicity (Causasian)	−8.74 ± 3.73	0.02
Total animal protein	Single isotope	NIR	13.95 ± 2.46	<0.01	0.18
	Multiple isotope	NIR	11.31 ± 2.44	<0.01	0.30
		CIR	10.17 ± 2.11	<0.01
		SIR	−0.55 ± 1.17	0.63
	Final model2	NIR	11.76 ± 2.22	<0.01	0.40
		CIR	10.99 ± 1.98	<0.01
		BMI	0.85 ± 0.25	<0.01
		LPA	0.30 ± 0.07	<0.01
Red meat	Single isotope	CIR	21.41 ± 4.21	<0.01	0.15
	Multiple isotope	CIR	21.16 ± 4.36	<0.01	0.16
		NIR	−0.54 ± 5.30	0.92
		SIR	−3.74 ± 2.55	0.14
	Final model2	CIR	21.05 ± 4.16	<0.01	0.18
		BMI	1.22 ± 0.55	0.03
Egg	Single isotope	CIR	6.09 ± 2.36	<0.01	0.04
	Multiple isotope	CIR	5.75 ± 2.43	0.02	0.05
		NIR	2.18 ± 3.04	0.47
		SIR	0.33 ± 1.44	0.82
	Final model2	CIR	6.05 ± 2.33	0.01	0.08
		BMI	0.58 ± 0.31	0.07
		LPA	0.17 ± 0.09	0.07

¹Values are model ß ± SE, P, and R², n = 147 (total animal protein and red meat), n = 146 (fish/seafood), n = 145 (egg) due to exclusion of model outliers (Mahalobnis distance > 4). CIR, carbon isotope ratio; LPA, leisure physical activity; NIR, nitrogen isotope ratio; NPAAS-FS, Nutrition and Physical Activity Assessment Study Feeding Study; SIR, sulfur isotope ratio.

²Final models included isotope ratios and participant characteristics that remained significant on the basis of a backward-selection process (P = 0.1).