Protein Requirements After Bariatric Surgery

Inclusion Criteria: 1. Male aged 18 - 65 years, 2. Primary RYGB surgery one to ten years before, 3. Weight stable within 5% over the last 3 months, 4. Normotensive or blood pressure controlled with antihypertensive therapy, 5. Provision of informed consent to participate, Exclusion Criteria: 1. Current diagnosis of cancer or active cancer in the preceding 1 year, 2. Any chronic or acute disease which is known to affect amino acid absorption, metabolism, or requirements, 3. Weight loss after bariatric surgery of less than 40% of excess weight, 4. Weight regain after bariatric surgery greater than 20% of nadir weight, 5. Diabetes mellitus defined as a fasting plasma glucose concentration ≥ 7.0 mmol, or HbA1c less than 6.5%, or medical treatment for diabetes.