TABLE 2.

Association between protein intake and lean mass of the legs in men and women from the Framingham Offspring Cohort¹

	Quartiles of protein intake
	Quartile 1	Quartile 2	Quartile 3	Quartile 4	P-trend
Men, n	363	291	248	237
Total protein (median intake), g/d	64.9	70.8	79.2	101.1
Total Protein	17.17 ± 0.09a	17.25 ± 0.10a,b	17.36 ± 0.11a,b	17.59 ± 0.12b	0.005
Animal protein2	17.14 ± 0.10a	17.23 ± 0.10a,b	17.39 ± 0.11a,b	17.59 ± 0.12b	0.002
Plant protein2	17.38 ± 0.10	17.11 ± 0.11	17.44 ± 0.11	17.35 ± 0.11	0.70
Women, n	296	354	424	423
Total protein (median intake), g/d	57.8	63.1	73.5	93.4
Total protein	11.47 ± 0.07a,b	11.40 ± 0.07a	11.58 ± 0.06a,b	11.67 ± 0.06b	0.006
Animal protein2	11.45 ± 0.07a	11.44 ± 0.07a	11.56 ± 0.06a,b	11.71 ± 0.06b	0.003
Plant protein2	11.44 ± 0.07	11.59 ± 0.06	11.55 ± 0.06	11.57 ± 0.07	0.36

¹Values are least squares means ± SEs unless otherwise indicated. Total n = 1139 men and 1497 women. The primary predictor was energy-adjusted residuals added to a constant, in which the constant equals the protein intake for the mean energy intake of the study population. Least squares means were adjusted for age, height, percentage leg fat, energy intake, physical activity, health status, and women’s menopause status. Adjustment for multiple comparisons was conducted with the use of Tukey’s test. Labeled means in a row without a common letter differ, P < 0.05. P-trend considered significant when <0.05 and considered marginally significant when <0.1.

²Animal protein intake and plant protein intake were adjusted for each other in the same model.