The present study will seek to quantify the muscle protein synthetic response to a protein beverage consumed orally or through a nasogastric tube in healthy, young individuals.

Thirty healthy, young volunteers will receive a stable isotope tracer infusion (8.5h) combined with repeated blood and muscle sampling, in order to measure muscle protein synthesis rate in the postabsorptive state, and following oral placebo ingestion (n=10), oral protein ingestion (n=10), or enteral protein administration (n=10).

Inclusion Criteria:

• 18-40 years of age
• Body mass index between 18.5 and 30

Exclusion Criteria:

• Any diagnosed metabolic impairment (e.g. type 1 or 2 Diabetes)
• Any diagnosed cardiovascular disease
• Elevated blood pressure at the time of screening. (An average systolic blood pressure reading of ≥140 mmHg over two or more measurements and an average diastolic blood pressure of ≥90 mmHg over two or more measurements)
• Chronic use of any prescribed or over the counter pharmaceuticals (that may modulate muscle protein metabolism). This excludes oral contraceptives and contraceptive devices.
• A personal or family history of epilepsy, seizures or schizophrenia.
• Presence of an ulcer in the stomach or gut and/or strong history of indigestion
• Known pre-existing liver disease/condition
• Any known disorders in muscle metabolism
• Regular use of nutritional supplements
• Allergy to lidocaine
• Allergy to milk
• Current paracetamol use (i.e. use of paracetamol more than once a week)
• Pregnancy

Oral conditions are double blinded to participant and investigator, but enteral vs oral feeding is not blinded