To maximise the skeletal muscle adaptive response to resistance exercise, dietary protein amount and distribution are typically optimised, though less consideration is given to the origin of that protein. We characterised dietary protein intakes throughout the day, with the focus being on protein source (i.e. animal vs. non-animal) and form (i.e. whole-foods vs. isolated supplemental forms) from a cohort of young (18-40 y) resistance trained (training ≥3x/week for ≥6months; TRA; m, n=30; f, n=14) and recreationally active (active but not engaged in structured training; REC; m, n=30; f, n=30) individuals. Using 3-day weighed food diaries obtained from 10 previously conducted human nutritional physiology studies, we retrospectively assessed daily macro-nutrient intakes in a standardised manner using dietary analysis software (Nutritics Dublin, Ireland). Energy intakes tended to be greater in TRA compared with REC (10.2±2.9 vs. 8.6±2.8 MJ·d-1, respectively; P=0.056) and were greater in males compared with females (10.0±1.6 vs. 8.3±0.0 MJ·d-1, respectively; P=0.006). TRA consumed a greater (P=0.002) proportion of daily energy intake as protein compared with REC (23±6 vs. 19±5 %TotMJ) which also tended to be greater in males compared with females (22±3 vs. 20±2 %TotMJ; P=0.06). Absolute (P<0.0001) and relative (to body mass [bm]; P<0.001) protein intakes were greater in TRA (males, 159±54 g·d-1 or 1.6±0.7 g·kg-1 bm·d-1; females, 105±40 g·d-1 or 2.0±0.6 g·kg-1bm·d-1: P<0.001) compared with REC (males, 101±37 g·d-1 or 1.3±0.5 g·kg-1 bm·d-1; females, 85±23 g·d-1 or 1.3±0.4 g·kg-1 bm·d-1: P<0.001), with absolute (P=0.025) but not relative (P=0.129) intakes being greater in males. Daily protein distribution followed a skewed pattern in both TRA (dinner, 49±25 > lunch, 39±25 > breakfast, 27±14 g·d-1; P=0.001) and REC (dinner, 39±17 > lunch, 26±13 > breakfast, 15±10 g·d-1; P=0.001), with TRA consuming more protein at breakfast (P<0.0001) and lunch (P=0.012). A greater proportion of total protein was consumed from animal- compared with non-animal- derived sources in TRA (68 vs. 32%, respectively; P<0.0001) and REC (64 vs. 36%, respectively; P<0.001), but that skew being present in males (72 vs. 28%, respectively; P<0.0001) and not females (56 vs. 44%, respectively; P=0.288). To a similar extent in both training statuses and sexes, a greater proportion (~88%) of total protein was consumed as whole-foods compared with supplemental protein (P<0.0001). We show that animal- and wholefood- derived proteins contribute the majority to daily dietary protein intakes in trained and recreationally active young men and women. Given current (sports nutrition) dietary protein guidelines are underpinned primarily from studies investigating isolated animal derived proteins, more mechanistic studies to investigate protein-rich whole-foods from a range of sources are warranted.
New Perspectives on the Physiological Basis of Muscle Loss (University of Exeter, UK) (2024) Proc Physiol Soc 60, C04
Oral Communications: The contribution of whole-food and supplemental derived dietary protein, from animal and non-animal origins, to daily protein intakes in young adults: a cross-sectional analysis.
Freyja A.D. Haigh1, Gráinne Whelehan1, George F. Pavis1, Sam West1, Marianna Apicella1, Tom S.O. Jameson1, Kiera Wilkinson1, Ino van der Heijden1, Alistair J. Monteyne1, Marlou L. Dirks1, Francis B. Stephens1, Benjamin T. Wall1,
1University of Exeter Exeter United Kingdom, 2Wageningen University Wageningen Netherlands, 3Nutritional Physiology Research Group, University of Exeter Exeter United Kingdom,
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Where applicable, experiments conform with Society ethical requirements.