The objective of this research project is to determine in elderly subjects (>50 year old) by 31P-MRS the brain concentration of phosphorous metabolites species and fluxes, before and after consumption of 2 commercially available oral nutrition products

Inclusion Criteria:

• Men and women aged between 50 and 75 years
• Healthy, based on the medical screening visit
• Normal BMI for age (18.5-29.9 kg/m2)
• Able to understand and to sign a written informed consent prior to trial entry
• Informed consent signed

Exclusion Criteria:

• Known type 1 or type 2 diabetes, on anamnesis

• Family history of type 2 diabetes (parents)

• Any other metabolic disease possibly impacting the postprandial glucose and insulin response (on anamnesis, to the opinion of the medical expert)

• Malabsorptive disorders including but not limited to pancreatitis, Crohn's disease, etc, to the opinion of the medical expert

• Any ongoing medication impacting dietary fat absorption and metabolism like statins, bile acid sequestrants, lipid lowering medications, or fibrates , to the opinion of the medical expert

• Any ongoing medication impacting the postprandial glucose and insulin response (like beta blockers), to the opinion of the medical expert

• Any ongoing medication impacting brain metabolism or function (neuroleptics, antidepressants, anti-epileptics), to the opinion of the medical expert

• Ongoing chemotherapy

• Any food supplement intake (e.g. MCT, ketone salts = Calcium, Sodium, Potassium, Magnesium) or special diet (e.g. ketogenic diet) possibly impacting basal ketone levels, to the opinion of the medical expert.

• Claustrophobia

• Hearing disorders (the participant placed into the MRS tunnel should be able to hear from the operators, for safety purpose)

• Having any metallic, electronic, magnetic, or mechanical implants, devices, or objects, for safety reason linked to magnetic field exposure (MRS):

  • Aneurysm clip(s)
  • Cardiac pacemaker
  • Implanted cardioverter defibrillator (ICD)
  • Electronic implant or device
  • Magnetically-activated implant or device
  • Neurostimulation system
  • Spinal cord stimulator
  • Cochlear implant or implanted hearing aid
  • Insulin or infusion pump
  • Implanted drug infusion device, like portacath® for instance
  • Any type of prosthesis or implant
  • Artificial or prosthetic limb
  • Any metallic fragment or foreign body
  • Hearing aid
  • Other implant

• Subject injured by a metallic object or foreign body

• Allergy to cow milk or soy proteins

• Currently participating or having participated in an investigational trial during the past month

• Subjects not willing and/or not able to comply with scheduled visits and the requirements of the research protocol.

• Subject having a hierarchical link with the investigator or co-investigators.