The Effect of Ketone Monoesters on Skeletal Muscle Protein Synthesis and Whole-body Protein Metabolism.

The ketone β-hydroxybutyrate (BHB) is endogenously produced during periods of low glucose availability, serving as an alternative metabolic fuel. Beyond its role as an energy substrate, BHB acts as a pleiotropic signalling molecule, modulating various physiological processes across multiple tissues. BHB can also be ingested orally as a ketone monoester, transiently elevating plasma concentrations of BHB to a level similar to those seen following several days of fasting, thereby obviating the need for dietary manipulation. The influence of BHB on human skeletal muscle protein metabolism remains poorly understood, although emerging evidence suggests that BHB may play a role in regulating muscle protein turnover. As such, BHB supplementation may support skeletal muscle remodelling and offer therapeutic benefits, and investigating this is of considerable interest. This study will investigate the ability of oral BHB ingestion - co-ingested with protein - to stimulate skeletal muscle anabolism in young healthy adults. A dual amino acid stable isotope tracer approach will be utilised to determine postprandial (i.e., fed state) muscle protein synthesis (MPS) rates and whole-body amino acid kinetics, given BHBs systemic effects. This research will advance our understanding of the fundamental biology of exogenous ketosis and provide insight into the potential of BHB supplementation as a novel nutritional strategy to optimise muscle mass and quality.