10.1016/j.clnu.2020.07.019 ">
 

Effects of high versus standard essential amino acid intakes on whole-body protein turnover and mixed muscle protein synthesis during energy deficit: A randomized, crossover study

Jess A. Gwin, United States Army Research Institute of Environmental Medicine
David D. Church, University of Arkansas for Medical Sciences
Adrienne Hatch-McChesney, United States Army Research Institute of Environmental Medicine
Emily E. Howard, United States Army Research Institute of Environmental Medicine
Christopher T. Carrigan, United States Army Research Institute of Environmental Medicine
Nancy E. Murphy, United States Army Research Institute of Environmental Medicine
Marques A. Wilson, United States Army Research Institute of Environmental Medicine
Lee M. Margolis, United States Army Research Institute of Environmental Medicine
John W. Carbone, Eastern Michigan University
Robert R. Wolfe, University of Arkansas for Medical Sciences
Arny A. Ferrando, University of Arkansas for Medical Sciences
Stefan M. Pasiakos, United States Army Research Institute of Environmental Medicine

Abstract

© 2020 Background & aims: Consuming 0.10–0.14 g essential amino acids (EAA)/kg/dose (0.25–0.30 g protein/kg/dose) maximally stimulates muscle protein synthesis (MPS) during energy balance. Whether consuming EAA beyond that amount enhances MPS and whole-body anabolism following energy deficit is unknown. The aims of this study were to determine the effects of standard and high EAA ingestion on mixed MPS and whole-body protein turnover following energy deficit. Design: Nineteen males (mean ± SD; 23 ± 5 y; 25.4 ± 2.7 kg/m2) completed a randomized, double-blind crossover study consisting of two, 5-d energy deficits (−30 ± 4% of total energy requirements), separated by 14-d. Following each energy deficit, mixed MPS and whole-body protein synthesis (PS), breakdown (PB), and net balance (NET) were determined at rest and post-resistance exercise (RE) using primed, constant L-[2H5]-phenylalanine and L-[2H2]-tyrosine infusions. Beverages providing standard (0.1 g/kg, 7.87 ± 0.87 g) or high (0.3 g/kg, 23.5 ± 2.54 g) EAA were consumed post-RE. Circulating EAA were measured. Results: Postabsorptive mixed MPS (%/h) at rest was not different (P = 0.67) between treatments. Independent of EAA, postprandial mixed MPS at rest (standard EAA, 0.055 ± 0.01; high EAA, 0.061 ± 0.02) and post-RE (standard EAA, 0.055 ± 0.01; high EAA, 0.065 ± 0.02) were greater than postabsorptive mixed MPS at rest (P = 0.02 and P = 0.01, respectively). Change in (Δ postabsorptive) whole-body (g/180 min) PS and PB was greater for high than standard EAA [mean treatment difference (95% CI), 3.4 (2.3, 4.4); P = 0.001 and −15.6 (−17.8, −13.5); P = 0.001, respectively]. NET was more positive for high than standard EAA [19.0 (17.3, 20.7); P = 0.001]. EAA concentrations were greater in high than standard EAA (P = 0.001). Conclusions: These data demonstrate that high compared to standard EAA ingestion enhances whole-body protein status during underfeeding. However, the effects of consuming high and standard EAA on mixed MPS are the same during energy deficit. Clinical trial registry: NCT03372928, https://clinicaltrials.gov.