This study was designed to obtain information about the change in postprandial amino acids in blood over time, after consumption of different dairy products, in an elderly population and how this relates to gastric emptying rate and feelings of satiety.

Inclusion Criteria:

• Age over 60y
• BMI 21-30 kg/m2
• Non-smoking
• Healthy as assessed by the NIZO lifestyle and health questionnaire
• Regular and normal Dutch eating habits as assessed by the NIZO lifestyle and health questionnaire (3 main meals per day)
• Veins suitable for cannulation (blood sampling)

Exclusion Criteria:

• Participation in any clinical trial including blood sampling and/or administration of substances up to 30 days before Day 01 of this study
• Having a history of medical or surgical events that may significantly affect the study outcome, including: Inflammatory bowel disease, hepatitis, pancreatitis, ulcers, gastrointestinal or rectal bleeding; major gastrointestinal tract surgery such as gastrectomy, gastroenterostomy, or bowel resection; known or suspected gastrointestinal disorders, colon or GI tract cancer
• Use of the following medication: glucose lowering drugs, insulin; medication that may impact gastric emptying (e.g. gastric acid inhibitors or laxatives)
• Diagnosed with diabetes, being treated for high blood glucose or increased fasting blood glucose (> 7 mmol/l in finger prick blood) as assessed during screening visit
• For men: Hb <8,5 mmol/l as assessed during screening visit; for women: Hb <7,5 mmol/l.
• Use of protein supplements
• Mental status that is incompatible with the proper conduct of the study
• A self-reported reported food allergy or sensitivity to dairy ingredients
• A self-reported allergy or sensitivity to acetaminophen
• Alcohol consumption > 28 units/week and 4/day
• Reported unexplained weight loss or weight gain of > 3 kg in the month prior to pre-study screening, or intention to lose weight during the study period
• Reported slimming or medically prescribed diet
• Recent blood donation (<1 month prior to Day 01 of the study)
• Not willing or afraid to give up blood donation during the study
• Personnel of NIZO food research or Wageningen University, department of Human Nutrition, their partner and their first and second degree relatives
• Not having a general practitioner
• Not willing to accept information-transfer concerning participation in the study, or information regarding his health, like laboratory results and eventual adverse events to and from his general practitioner