Low-fat pork ingestion promotes greater postexercise myofibrillar protein synthesis compared to high-fat pork and carbohydrate beverage in young adults

The nutrient-nutrient interactions within a food matrix may alter the postprandial stimulation of myofibrillar protein synthesis rates (MPS). We have previously shown that a protein- and lipid-rich food matrix has greater anabolic potential compared to the ingestion of a low-fat, protein-rich food matrix. Objectives: Thus, this study aimed to investigate the effects of consuming a high-fat pork (HFP) compared to low-fat pork (LFP) product and a carbohydrate control drink (CHO) on postexercise stimulation of MPS. Hypothesis: We hypothesized that the ingestion of HFP and LFP would increase MPS compared to CHO. We further hypothesize that the ingestion of HFP will further potentiate the stimulation of MPS than the LFP condition. Methods: In a semi-crossover design, 16 physically-active adults (25±5; BMI: 25.0 ± 2.3 kg·m -2 ; 12M, 4 F) underwent primed constant infusions of L-[ ring - 13 C 6 ]phenylalanine and performed an acute bout of resistance exercise. Following resistance exercise, participants ingested either HFP (81% lean; 266 kcal, 20 g protein, and 20.6 g fat), LFP (95% lean; 120 kcal, 20 g protein, 4.4 g fat), or CHO (266 kcal, 0 g protein, 0 g fat, 73.3 g carbohydrate; Gatorade). During their second trial, participants were randomly assigned to one of the two remaining conditions in a counterbalanced fashion (resulting in n = 10 per condition). Repeated blood and muscle samples were collected at rest and throughout the 5 h postexercise recovery period for measurement of plasma amino acid concentrations and MPS. Data were analyzed using linear fixed effects models with time and group as fixed factors and Bonferroni post hoc analysis when significant ( P < 0.05) differences were detected. Results: Plasma essential amino acid (EAA) and leucine concentrations increased after ingestion of HFP and LFP (both P < 0.001), with greater peak plasma EAA and leucine concentrations in LFP treatment compared to HFP ( P = 0.018 and P = 0.027, respectively) and CHO (both P < 0.001). Incremental area under the curve (iAUC) for plasma EAA and leucine concentrations did not differ between LFP and HFP ( P = 0.350 and P = 0.361, respectively), however, both conditions resulted in significantly higher iAUC as compared to CHO treatment (both P < 0.001). Both HFP and LFP stimulated MPS above resting values ( P = 0.028 and P < 0.001, respectively). Postexercise MPS was significantly greater in LFP (0.095 ± 0.029 %·h -1 ) compared to HFP (0.065 ± 0.024 %·h -1 ; P = 0.030) and CHO (0.052 ± 0.033 %/h -1 ; P < 0.001). Conclusions: LFP ingestion immediately after resistance exercise results in greater stimulation of MPS than HFP and CHO. Our findings indicate that the nutrient profile of protein-rich foods uniquely modulates postexercise muscle anabolism compared to the protein content alone in healthy adults. This study was funded by the National Pork Board (project no. #22-040). This abstract was presented at the American Physiology Summit 2025 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.