Inclusion Criteria:  Age 35-65 Healthy Non-smoker Recreationally active  Exclusion Criteria:  Any diagnosed metabolic impairment (e.g. type 1 or 2 Diabetes) Any diagnosed cardiovascular disease or hypertension Elevated blood pressure at the time of screening. (An average systolic blood pressure reading of ≥150mmHg over two or more measurements and an average diastolic blood pressure of ≥90mmHg over two or more measurements.) Chronic use of diabetic medication. A personal or family history of epilepsy, seizures or schizophrenia. Allergic to mycoprotein / Quorn, penicillin, or cow's milk. Any musculoskeletal injury that may impair their use of crutches. Any diagnosed severe digestive illness. Any diagnosed severe autoimmune disease. Any diagnosed cancer. Any metal fragments in your eyes, a pacemaker, or metal implants in your body that preclude MRI scanning.