Metabolic Availability in Older and Younger Men

Inclusion Criteria: Gender: Male Age: 20-35 years or 65-80 years Body Mass Index (BMI): 18.5 - 30.0 kg/m2 Healthy as assessed with a questionnaire Regular and normal eating habits as assessed with a Food Frequency Questionnaire (FFQ) Willing to comply with study procedures and use of data Having given written informed consent Exclusion Criteria: Chronic disease, for example: * Diabetes mellitus / being treated for high blood glucose * Severe cardiovascular disease (exception: hypertension) * Hepatic disease (e.g. hepatitis) * Renal disease * Cancer * Bowel disease (e.g. inflammatory bowel disease, ulcers, bleeding) * Pancreatitis History of medical or surgical events that may affect GI function, and the study outcomes or disease risk for participants, for example: * Bariatric surgery * Gastrointestinal tract surgery * Digestive tract disorder * Chewing problems * History of deep venous thrombosis without anti-coagulation medication Medicine use that interferes with, protein metabolism, GI function and the study outcomes, for example: * Glucose lowering drugs * Proton pump inhibitors * Laxatives Habits that interfere with the study outcomes: * Protein supplement use (current use or less than 2 weeks past use) * Smoking * Drug use * Alcohol consumption \>21 units/week and/or \>4/day * Following a weight-loss diet, medically prescribed diet or other diet with a low calorie intake or an unbalanced nutrient intake like a vegan or very low carbohydrate diet * Moderate to …