Consumption of whole eggs promotes greater stimulation of postexercise muscle protein synthesis than consumption of isonitrogenous amounts of egg whites in young men

Abstract

Background: Protein in the diet is commonly ingested from whole foods that contain various macro-and micronutrients. However, the effect of consuming protein within its natural whole-food matrix on postprandial protein metabolism remains understudied in humans. Objective: We aimed to compare the whole-body and muscle protein metabolic responses after the consumption of whole eggs with egg whites during exercise recovery in young men. Design: In crossover trials, 10 resistance-trained men [aged 21 6 1 y; 88 6 3 kg; body fat: 16% 6 1% (means 6 SEMs)] received primed continuous L-[ring- H 3 ]leucine-labeled whole eggs (18 g protein, 17 g fat) or egg whites (18 g protein, 0 g fat). Repeated blood and muscle biopsy samples were collected to assess whole-body leucine kinetics, intramuscular signaling, and myofibrillar protein synthesis. Results: Plasma appearance rates of protein-derived leucine were more rapid after the consumption of egg whites than after whole eggs (P = 0.01). Total plasma availability of leucine over the 300-min postprandial period was similar (P = 0.75) between the ingestion of whole eggs (68% 6 1%) and egg whites (66% 6 2%), with no difference in whole-body net leucine balance (P = 0.27). Both whole-egg and egg white conditions increased the phosphorylation of mammalian target of rapamycin complex 1, ribosomal protein S6 kinase 1, and eukaryotic translation initiation factor 4E-binding protein 1 during postexercise recovery (all P , 0.05). However, whole-egg ingestion increased the postexercise myofibrillar protein synthetic response to a greater extent than did the ingestion of egg whites (P = 0.04). Conclusions: We show that the ingestion of whole eggs immediately after resistance exercise resulted in greater stimulation of myofibrillar protein synthesis than did the ingestion of egg whites, despite being matched for protein content in young men. Our data indicate that the ingestion of nutrient-and protein-dense foods differentially stimulates muscle anabolism compared with protein-dense foods. This trial was registered at clinicaltrials.gov as NCT03117127.

The impact of exercise and nutrition on the regulation of skeletal muscle mass

“…whole egg (both providing 18 g of dietary protein) consumption during post‐exercise recovery in healthy young men revealed a superior 5 h MPS response after whole egg ingestion, despite similar postprandial amino acid profiles after ingestion of these two protein sources (van Vliet et al . ). These findings confirmed the results of a previous study in which whole milk consumption resulted in a greater net uptake of amino acids by skeletal muscle (presumably for use in protein synthesis) compared to ingestion of skimmed milk matched for protein content (Elliot et al .…”

Nutrition tactics to improve post-exercise recovery

“…However, subjects were able to continue to exercise for 15 to 70 minutes despite being hypoglycemic and their time to exhaustion was not significantly different from euglycemic subjects. Glucose ingestion at rates of 40 or 80 g•h −1 prevented the hypoglycemia, but did not significantly increase time to fatigue [58].…”

“…However, the impact of hypoglycemia or its prevention does not always consistently improve endurance capacity [57,58]. Felig et al observed hypoglycemia in approximately one third of subjects cycling to exhaustion on 60-65% VO2max in a fasted state [58].…”

“…However, the impact of hypoglycemia or its prevention does not always consistently improve endurance capacity [57,58]. Felig et al observed hypoglycemia in approximately one third of subjects cycling to exhaustion on 60-65% VO2max in a fasted state [58]. However, subjects were able to continue to exercise for 15 to 70 minutes despite being hypoglycemic and their time to exhaustion was not significantly different from euglycemic subjects.…”

“…This absence of a delay in protein digestion and amino acid absorption kinetics may be attributed to layering of fat on top of protein in the stomach that may only occur with a liquid meal [57]. However, co-ingestion of 17 g fat as provided by the consumption of whole eggs did not attenuate post-exercise protein digestion and amino acid absorption kinetics when compared to the ingestion of an isonitrogenous amount of egg whites [58]. Therefore, fat co-ingestion does not appear to substantially impact protein digestion and amino acid absorption kinetics.…”