Background Mycoprotein is a fungal-derived sustainable protein-rich food source, and its ingestion results in systemic amino acid and leucine concentrations similar to that following milk protein ingestion. Objective We assessed the mixed skeletal muscle protein synthetic response to the ingestion of a single bolus of mycoprotein compared with a leucine-matched bolus of milk protein, in rested and exercised muscle of resistance-trained young men. Methods Twenty resistance-trained healthy young males (age: 22 ± 1 y, body mass: 82 ± 2 kg, BMI: 25 ± 1 kg·m−2) took part in a randomized, double-blind, parallel-group study. Participants received primed, continuous infusions of L-[ring-2H5]phenylalanine and ingested either 31 g (26.2 g protein: 2.5 g leucine) milk protein (MILK) or 70 g (31.5 g protein: 2.5 g leucine) mycoprotein (MYCO) following a bout of unilateral resistance-type exercise (contralateral leg acting as resting control). Blood and m. vastus lateralis muscle samples were collected before exercise and protein ingestion, and following a 4-h postprandial period to assess mixed muscle fractional protein synthetic rates (FSRs) and myocellular signaling in response to the protein beverages in resting and exercised muscle. Results Mixed muscle FSRs increased following MILK ingestion (from 0.036 ± 0.008 to 0.052 ± 0.006%·h−1 in rested, and 0.035 ± 0.008 to 0.056 ± 0.005%·h−1 in exercised muscle; P <0.01) but to a greater extent following MYCO ingestion (from 0.025 ± 0.006 to 0.057 ± 0.004%·h−1 in rested, and 0.024 ± 0.007 to 0.072 ± 0.005%·h−1 in exercised muscle; P <0.0001) (treatment × time interaction effect; P <0.05). Postprandial FSRs trended to be greater in MYCO compared with MILK (0.065 ± 0.004 compared with 0.054 ± 0.004%·h−1, respectively; P = 0.093) and the postprandial rise in FSRs was greater in MYCO compared with MILK (Delta 0.040 ± 0.006 compared with Delta 0.018 ± 0.005%·h−1, respectively; P <0.01). Conclusions The ingestion of a single bolus of mycoprotein stimulates resting and postexercise muscle protein synthesis rates, and to a greater extent than a leucine-matched bolus of milk protein, in resistance-trained young men. This trial was registered at clinicaltrials.gov as 660065600.

Mycoprotein consumption has been shown to improve acute postprandial glycaemic control and decrease circulating cholesterol concentrations. We investigated the impact of incorporating mycoprotein into the diet on insulin sensitivity (IS), glycaemic control and plasma lipoprotein composition. Twenty healthy adults participated in a randomised, parallel-group trial in which they consumed a 7 d fully-controlled diet where lunch and dinner contained either meat/fish (CON) or mycoprotein (MYC) as the primary source of dietary protein. Oral glucose tolerance tests were performed pre- and post- intervention, and 24h continuous blood glucose monitoring was applied throughout. Fasting plasma samples were obtained pre- and post- intervention and were analysed using quantitative, targeted NMR-based metabonomics. There were no changes within or between groups in blood glucose or serum insulin responses, nor in IS (Cederholm; 51±3 to 51±3 and 54±3 to 53±3 mg.L2/mmol.mU.min in CON and MYC, respectively; P<0.05) or 24 h glycaemic profiles. No differences between groups were found for 171 of the 224 metabonomic targets. Forty five lipid concentrations of different lipoprotein fractions (VLDL, LDL, IDL and HDL) remained unchanged in CON but showed a coordinated decrease (7-27 %; all P<0.05) in MYC. Total plasma cholesterol, free-C, LDL-C, HDL2-C, DHA and omega-3 fatty acids decreased to a larger degree in MYC (14-19 %) compared with CON (3-11 %; P<0.05). Substituting meat/fish for mycoprotein twice-daily for one week did not modulate whole-body IS or glycaemic control but resulted in changes to plasma lipid composition; the latter primarily consisting of a coordinated reduction in circulating cholesterol containing lipoproteins.

The world’s population is expanding, leading to an increased global requirement for dietary protein to support health and adaptation in various populations. Though a strong evidence base supports the nutritional value of animal-derived dietary proteins, mounting challenges associated with sustainability of these proteins have led to calls for the investigation of alternative, non–animal-derived dietary protein sources. Mycoprotein is a sustainably produced, protein-rich, high-fiber, whole food source derived from the fermentation of fungus. Initial investigations in humans demonstrated that mycoprotein consumption can lower circulating cholesterol concentrations. Recent data also report improved acute postprandial glycemic control and a potent satiety effect following mycoprotein ingestion. It is possible that these beneficial effects are attributable to the amount and type of dietary fiber present in mycoprotein. Emerging data suggest that the amino acid composition and bioavailability of mycoprotein may also position it as a promising dietary protein source to support skeletal muscle protein metabolism. Mycoprotein may be a viable dietary protein source to promote training adaptations in athletes and the maintenance of muscle mass to support healthy aging. Herein, current evidence underlying the metabolic effects of mycoprotein is reviewed, and the key questions to be addressed are highlighted.

Animal-derived dietary protein ingestion and physical activity stimulate myofibrillar protein synthesis rates in older adults. We determined whether a non-animal-derived diet can support daily myofibrillar protein synthesis rates to the same extent as an omnivorous diet. Nineteen healthy older adults (age 66±1 y; BMI 24±1 kg·m-2; m=12, f=7) participated in a randomised, parallel-group, controlled trial during which they consumed a 3-day isocaloric high-protein (1.8 g·kg body mass-1·d-1) diet, where the protein was provided from predominantly (71%) animal (OMNI; n=9; m=6, f=3) or exclusively vegan (VEG; n=10; m=6, f=4; mycoprotein providing 57% of daily protein intake) sources. During the dietary control period participants conducted a daily bout of unilateral resistance-type leg extension exercise. Prior to the dietary control period participants ingested 400 mL deuterated water, with 50 mL doses consumed daily thereafter. Saliva samples were collected throughout to determine body water deuterium (2H) enrichments, and muscle samples were collected from rested and exercised muscle to determine daily myofibrillar protein synthesis rates. Deuterated water dosing resulted in body water 2H enrichments of ~0.78±0.03%. Daily myofibrillar protein synthesis rates were 13±8 (P=0.169) and 12±4% (P=0.016) greater in the exercised compared with rested leg (1.59±0.12 vs 1.77±0.12 %·d-1 and 1.76±0.14 vs 1.93±0.12 %·d-1) in OMNI and VEG groups, respectively. Daily myofibrillar protein synthesis rates did not differ between OMNI and VEG in either rested or exercised muscle (P>0.05). Over the course of a three day intervention, omnivorous or vegan derived dietary protein sources can support equivalent rested and exercised daily myofibrillar protein synthesis rates in healthy older adults consuming a high-protein diet.

Background We have shown that ingesting a large bolus (70 g) of the fungal-derived, whole food mycoprotein robustly stimulates muscle protein synthesis (MPS) rates. Objective The aim of this study was to determine if a lower dose (35 g) of mycoprotein enriched with branched-chain amino acids (BCAAs) stimulates MPS to the same extent as 70 g of mycoprotein in resistance-trained young men. Methods Nineteen men [aged 22 ± 1 y, BMI (kg/m2): 25 ± 1] took part in a randomized, double-blind, parallel-group study. Participants received primed, continuous infusions of l-[ring-2H5]phenylalanine and ingested either 70 g mycoprotein (31.5 g protein; MYCO; n = 10) or 35 g BCAA-enriched mycoprotein (18.7 g protein: matched on BCAA content; ENR; n = 9) following a bout of unilateral resistance exercise. Blood and bilateral quadriceps muscle samples were obtained before exercise and protein ingestion and during a 4-h postprandial period to assess MPS in rested and exercised muscle. Two- and 3-factor ANOVAs were used to detect differences in plasma amino acid kinetics and mixed muscle fractional synthetic rates, respectively. Results Postprandial plasma BCAA concentrations increased more rapidly and to a larger degree in ENR compared with MYCO. MPS increased with protein ingestion (P ≤ 0.05) but to a greater extent following MYCO (from 0.025% ± 0.006% to 0.057% ± 0.004% · h−1 in rested muscle, and from 0.024% ± 0.007% to 0.072% ± 0.005% · h−1 in exercised muscle; P &lt; 0.0001) compared with ENR (from 0.031% ± 0.003% to 0.043% ± 0.005% · h−1 in rested muscle, and 0.027% ± 0.005% to 0.052% ± 0.005% · h−1 in exercised muscle; P &lt; 0.01) ingestion. Postprandial MPS rates were greater in MYCO compared with ENR (P &lt; 0.01). Conclusions The ingestion of lower-dose BCAA-enriched mycoprotein stimulates resting and postexercise MPS rates, but to a lesser extent compared with the ingestion of a BCAA-matched 70-g mycoprotein bolus in healthy young men. This trial was registered at clinicaltrials.gov as 660065600.