The Contribution of Whole-Food and Supplemental Derived Dietary Protein, From Animal and Nonanimal Origins, to Daily Protein Intake in Young Adults: A Cross-Sectional Analysis

We characterized daily dietary protein intakes, focusing on protein source (animal and nonanimal) and form (whole-foods and supplemental) in young (18-40 years) resistance trained (training ≥ 3×/week for ≥ 6 months; TRA; male, n = 30; female, n = 14) and recreationally active (no structured training; REC; male, n = 30; female, n = 30) individuals. Using 3-day weighed food diaries from 10 previous studies, we assessed macronutrient intakes using dietary analysis software. Energy intakes trended greater in TRA compared with REC (p = .056) and were greater in males than females (p = .006). TRA consumed greater (p = .002) proportions of daily energy intake as protein than REC (23 ± 6 vs. 19 ± 5%Energy), which also trended greater in males compared with females (22 ± 3 vs. 20 ± 2%Energy; p = .060). Absolute (p < .001) and relative (to body mass [BM]; p < .001) protein intakes were greater in TRA (males, 159 ± 54 g/day or 1.6 ± 0.7 g·kg-1 BM·day-1; females, 105 ± 40 g/day or 2.0 ± 0.6 g·kg-1 BM·day-1; p < .001) than REC (males, 103 ± 37 g/day or 1.3 ± 0.5 g·kg-1 BM·day-1; females, 85 ± 23 g/day or 1.3 ± 0.4 g·kg-1 BM·day-1; p < .001), with absolute (p = .025), but not relative (p = .129) intakes greater in males. A greater proportion of total protein was consumed from animal compared with nonanimal in TRA (68% vs. 32%, respectively; p < .001) and REC (64% vs. 36%, respectively; p < .001); the skew driven exclusively by males (72% vs. 28%, respectively; p < .001). A greater proportion (∼92%) of total protein was consumed as whole-foods compared with supplemental, irrespective of training status or sex (p < .001). We show animal and whole-food-derived proteins contribute the majority to daily dietary protein intakes in TRA and REC young males and females.