Study to Compare Milk Protein Isolate (MPI) With Caseinate in Terms of Protein Utilization

Inclusion Criteria: To be considered eligible for enrolment into the study, subjects must; 1. Be able to give written informed consent. 2. Be between 65 and 75 years of age. 3. Be in generally good health as determined by the investigator. 4. Have no evidence of gastrointestinal disease or of a functional gastrointestinal disorder as determined by the Bowel Disease Questionnaire. 5. Have a stable body weight over the past 3-months. 6. Have a Body Mass Index (BMI) greater than 22, for males and 20 for females and less than 30. 7. Have a satisfactory nutritional status. Exclusion Criteria: Subjects will be excluded from the study if they meet any of the below criteria; 1. Are less than 65 and greater than 75 years of age. 2. Have evidence of gastrointestinal disease or other functional gastrointestinal disorder as determined by the Bowel Disease Questionnaire. 3. Have a significant acute or chronic coexisting illness (cardiovascular, gastrointestinal, endocrinological, immunological, metabolic or any condition which contraindicates, in the investigators judgement, entry to the study). 4. Having a condition or taking a medication that the investigator believes would interfere with the objectives of the study, pose a safety risk or confound the interpretation of the study results; to include anti-inflammatory drugs, corticosteroids, laxatives, enemas, antibiotics (within 1 month), anti-coagulants, and over-the counter non-steroidal analgesics. Subjects should have a wash-out period of two-weeks. 5. Be a smoker. 6. Consume more than the recommended alcohol guidelines i.e. 3-4 alcohol units a day for a man and for a woman 2-3 units a day. 7. Suffer from psychiatric disease 8. Prior gastrointestinal surgery (apart from appendicectomy and hernia repair) or recent unexplained bleeding. 9. Have dietary habits (slimming or vegetarian diet) which could interfere with the assessment of the study product. 10. Individuals who, in the opinion of the investigator, are considered to be poor attendees or unlikely for any reason to be able to comply with the trial. 11. Subjects may not be receiving treatment involving experimental drugs. 12. If the subject has been in a recent experimental trial, these must have been completed not less than 30 days prior to this study. 13. Have a malignant disease or any concomitant end-stage organ disease