Food matrix in the context of muscle and whole-body protein synthesis: a scoping review

Background Understanding the impact of food matrix, the combination of nutrients, bioactive compounds, and physical characteristics in a food product, on muscle protein synthesis (MPS), could provide insights on how to use different meals to promote muscle anabolism. The aim of this review was to explore the impact of the food matrix on MPS or whole-body PS. Methods PubMed, Scopus, Web of Science, and the Cochrane library were searched from inception until January 2024. A narrative synthesis was employed to synthesize the findings and the quality of the studies was assessed using the Cochrane risk-of-bias 2 tool for randomised trials (RoB 2). The study’s protocol was registered in PROSPERO (International Prospective Register of Systematic Reviews; CRD42024503306). Results Only one study was eligible to be included in this review. MPS was 0.035 ± 0.004 %/hr in the minced beef group vs. 0.034 ± 0.003 %/hr in beef steak, postprandially, showing no significant differences between groups. Increased whole-body PS response was observed after the consumption of minced beef compared to beef steak (29 ± 2 mmol phenylalanine/kg vs. 19 ± 3 mmol phenylalanine/kg, respectively; P < 0.01). The overall risk of bias was considered low. Conclusions Future studies should use food products with identical nutrient composition to evaluate the influence of the food matrix on MPS and whole-body PS, considering that current trials have primarily focused on ensuring similar protein intakes across study arms.