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OBJECTIVE: This study aimed to assess the impact of time-restricted eating (TRE) on integrated skeletal muscle myofibrillar protein synthesis (MyoPS) rates in males with overweight/obesity.METHODS: A total of 18 healthy males (age 46 ± 5 years; BMI: 30 ± 2 kg/m2 ) completed this exploratory, parallel, randomized dietary intervention after a 3-day lead-in diet. Participants then consumed an isoenergetic diet (protein: ~1.0 g/kg body mass per day) following either TRE (10:00 a.m. to 6:00 p.m.) or an extended eating control (CON; 8:00 a.m. to 8:00 p.m.) protocol for 10 days. Integrated MyoPS rates were measured using deuterated water administration with repeated saliva, blood, and muscle sampling. Secondary measures included continuous glucose monitoring and body composition (dual-energy x-ray absorptiometry).RESULTS: There were no differences in daily integrated MyoPS rates (TRE: 1.28% ± 0.18% per day, CON: 1.26% ± 0.22% per day; p = 0.82) between groups. From continuous glucose monitoring, 24-hour total area under the curve was reduced following TRE (-578 ± 271 vs. CON: 12 ± 272 mmol/L × 24 hours; p = 0.001). Total body mass declined (TRE: -1.6 ± 0.9 and CON: -1.1 ± 0.7 kg; p CONCLUSION: Consuming food within an 8-hour time-restricted period does not lower daily MyoPS rates when compared with an isoenergetic diet consumed over 12 hours. Future research should investigate whether these results translate to free-living TRE.

Background Protein ingestion increases muscle protein synthesis rates. The food matrix in which protein is provided can strongly modulate the postprandial muscle protein synthetic response. So far, the muscle protein synthetic response to the ingestion of whole foods remains largely unexplored. Objectives To compare the impact of ingesting 30 g protein provided as milk protein or cheese on postprandial plasma amino acid concentrations and muscle protein synthesis rates at rest and during recovery from exercise in vivo in young males. Methods In this randomized, parallel-group intervention trial, 20 healthy males aged 18-35 y ingested 30 g protein provided as cheese or milk protein concentrate following a single-legged resistance-type exercise session consisting of 12 sets of leg press and leg extension exercises. Primed, continuous intravenous L-[ring-C-13(6)]-phenylalanine infusions were combined with the collection of blood and muscle tissue samples to assess postabsorptive and 4-h postprandial muscle protein synthesis rates at rest and during recovery from exercise. Data were analyzed using repeated measures Time x Group (x Leg) ANOVA. Results Plasma total amino acid concentrations increased after protein ingestion (Time: P < 0.001), with 38% higher peak concentrations following milk protein than cheese ingestion (Time x Group: P < 0.001). Muscle protein synthesis rates increased following both cheese and milk protein ingestion from 0.037 +/- 0.014 to 0.055 +/- 0.018%center dot h(-1) and 0.034 +/- 0.008 to 0.056 +/- 0.010%center dot h(-1) at rest and even more following exercise from 0.031 +/- 0.010 to 0.067 +/- 0.013%center dot h(-1) and 0.030 +/- 0.008 to 0.063 +/- 0.010%center dot h(-1), respectively (Time: all P < 0.05; Time x Leg: P = 0.002), with no differences between cheese and milk protein ingestion (Time x Group: both P > 0.05). Conclusion Cheese ingestion increases muscle protein synthesis rates both at rest and during recovery from exercise. The postprandial muscle protein synthetic response to the ingestion of cheese or milk protein does not differ when 30 g protein is ingested at rest or during recovery from exercise in healthy, young males.

Background Plant-derived proteins are considered to have lesser anabolic properties when compared with animal-derived proteins. The attenuated rise in muscle protein synthesis rates following ingestion of plant-derived compared with animal-derived protein has been, at least partly, attributed to deficiencies in specific amino acids such as leucine, lysine, and/or methionine. Combining different plant-derived proteins could provide plant-derived protein blends with a more balanced amino acid profile. Objectives This study aimed to compare postprandial muscle protein synthesis rates following the ingestion of 30 g milk protein with a 30 g blend combining wheat, corn, and pea protein in healthy young men. Methods In a randomized, double-blind, parallel-group design, 24 young males (aged 24 ± 4 y) received a primed continuous L-[ring-13C6]-phenylalanine infusion after which they ingested 30 g milk protein (MILK) or a 30 g plant-derived protein blend combining 15 g wheat, 7.5 g corn, and 7.5 g pea protein (PLANT-BLEND). Blood and muscle biopsies were collected frequently for 5 h to assess postprandial plasma amino acid profiles (secondary outcome) and subsequent muscle protein synthesis rates (primary outcome). Data were analyzed by 2-factor repeated measures ANOVA and 2-samples t tests. Results MILK increased plasma essential amino acid concentrations more than PLANT-BLEND over the 5 h postprandial period (incremental AUC = 151 ± 31 compared with 79 ± 12 mmol·300 min·L−1, respectively; P < 0.001). Ingestion of both MILK and PLANT-BLEND increased myofibrillar protein synthesis rates (P < 0.001), with no significant differences between treatments (0.053 ± 0.013%/h and 0.064 ± 0.016%/h, respectively; P = 0.08). Conclusions Ingestion of 30 g plant-derived protein blend combining wheat-, corn-, and pea-derived protein increases muscle protein synthesis rates in healthy young males. The muscle protein synthetic response to the ingestion of 30 g of this plant-derived protein blend does not differ from the ingestion of an equivalent amount of a high-quality animal-derived protein. Clinical trial registry number for Nederlands Trial Register: NTR6548 (https://trialsearch.who.int/Trial2.aspx?TrialID=NTR6548).