Ingestion of diverse protein-rich whole-foods result in similar post exercise whole body and myofibrillar protein synthesis rates compared with a more isolated protein source in young adults

Abstract

Background: The ingestion of protein-rich whole-foods may stimulate (post exercise) whole body (WB) and myofibrillar protein synthesis (MyoPS) rates to a greater extent than more isolated protein sources.

Objectives: We assessed WB protein turnover and MyoPS rates after a bout of resistance exercise and ingestion of a variety of protein-rich whole-foods (animal and nonanimal) and egg whites (more isolated protein source) in resistance-trained young adults.

Methods: In a randomized parallel group design, 65 healthy individuals received primed, continuous infusions of L-[ring-²H₅]phenylalanine and L-[3,3-²H₂]tyrosine and completed a bout of lower-body resistance exercise before ingesting 0.25 g protein per kg body mass (bm) from: egg whites (n = 11), egg (n = 11), salmon (n = 10), pork (n = 11) lentils (n = 11) or mycoprotein (n = 11). Blood and muscle samples were taken pre- and (120 and 300 min) post exercise/food ingestion to determine WB phenylalanine kinetics and MyoPS rates. Calculated WB phenylalanine kinetics and fractional synthesis rates were analyzed using 2-way (group × time) analysis of variance.

Results: WB protein synthesis and breakdown rates increased and decreased, respectively, post exercise/food ingestion in all groups; though a greater positive WB net protein balance was achieved (primarily via greater suppression of breakdown) after egg white ingestion, despite similar insulinemia across all groups [postprandial net balance (0-300 min); egg whites, 256.6 ± 15.4 compared with.; egg, 161.0 ± 6.1; pork, 166.8 ± 7.2; salmon, 195.4 ± 7.1; lentils, 175.8 ± 8.1; mycoprotein, 189.7 ± 8.4 μmol/kg/min (P < 0.0001, all)]. MyoPS rates increased after exercise/food ingestion with no (temporal) differences between groups despite divergent plasma amino acid responses [Δ change in fractional synthesis rates (0-300 min); egg whites, 0.050 ± 0.013; egg, 0.051 ± 0.009; pork, 0.008 ± 0.008; salmon, 0.021 ± 0.014; lentils, 0.029 ± 0.012; mycoprotein, 0.041 ± 0.012% per hour (P = 0.077)].

Conclusions: The ingestion of a variety of protein-rich whole-foods or a more isolated protein source (egg whites) after lower-body exercise results in comparable MyoPS rates, though a greater WB net protein anabolism was achieved with egg whites. The trial was registered at clinicaltrials.gov (NCT04794153). Date of Registration: 2021-03-04. https://clinicaltrials.gov/study/NCT04794153?term=NCT04794153&rank=1 Clinical Trial Register No. (clinicaltrials.gov): NCT04794153.

Keywords: amino acids; muscle protein synthesis; protein metabolism; resistance exercise; whole-foods.