title: Protein Considerations for Optimising Skeletal Muscle Mass in Healthy Young and Older Adults.
abstract: Skeletal muscle is critical for human health. Protein feeding, alongside resistance exercise, is a potent stimulus for muscle protein synthesis (MPS) and is a key factor that regulates skeletal muscle mass (SMM). The main purpose of this narrative review was to evaluate the latest evidence for optimising the amino acid or protein source, dose, timing, pattern and macronutrient coingestion for increasing or preserving SMM in healthy young and healthy older adults. We used a systematic search strategy of PubMed and Web of Science to retrieve all articles related to this review objective. In summary, our findings support the notion that protein guidelines for increasing or preserving SMM are more complex than simply recommending a total daily amount of protein. Instead, multifactorial interactions between protein source, dose, timing, pattern and macronutrient coingestion, alongside exercise, influence the stimulation of MPS, and thus should be considered in the context of protein recommendations for regulating SMM. To conclude, on the basis of currently available scientific literature, protein recommendations for optimising SMM should be tailored to the population or context of interest, with consideration given to age and resting/post resistance exercise conditions.
authors.affiliation: Health &amp; Exercise Sciences Research Group, Faculty of Health Sciences and Sport, University of Stirling, Stirling FK9 4LA, UK. oliver.witard@stir.ac.uk.
authors.forename: Oliver C
authors.initials: OC
authors.lastname: Witard
authors.affiliation: Health &amp; Exercise Sciences Research Group, Faculty of Health Sciences and Sport, University of Stirling, Stirling FK9 4LA, UK. sophielwardle@gmail.com.
authors.forename: Sophie L
authors.initials: SL
authors.lastname: Wardle
authors.affiliation: Health &amp; Exercise Sciences Research Group, Faculty of Health Sciences and Sport, University of Stirling, Stirling FK9 4LA, UK. lindsay.macnaughton@stir.ac.uk.
authors.forename: Lindsay S
authors.initials: LS
authors.lastname: Macnaughton
authors.affiliation: Lucozade Ribena Suntory Limited, 2 Longwalk Road, Stockley Park, Uxbridge UB11 1BA, UK. Adrian.Hodgson@lrsuntory.com.
authors.forename: Adrian B
authors.initials: AB
authors.lastname: Hodgson
authors.affiliation: Health &amp; Exercise Sciences Research Group, Faculty of Health Sciences and Sport, University of Stirling, Stirling FK9 4LA, UK. k.d.tipton@stir.ac.uk.
authors.forename: Kevin D
authors.initials: KD
authors.lastname: Tipton
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging; D000596:Amino Acids / Q000008:administration & dosage / Q000494:pharmacology; D004032:Diet; D004044:Dietary Proteins / Q000008:administration & dosage* / Q000494:pharmacology*; D006801:Humans; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000254:growth & development* / Q000378:metabolism*
chemical_list: D000596:Amino Acids; D004044:Dietary Proteins
keywords: amino acid availability; macronutrient coingestion; muscle hypertrophy; muscle protein synthesis; protein dose; protein pattern; protein source; protein timing