Inclusion Criteria:  Participants are able to provide signed and dated written informed consent prior to any study specific procedures Aged ≥ 65 and ≤ 80 years Body mass index (BMI) 25 - 35 kg/m2 Stable dietary habits (no weight loss or gain > 5 kg in the past 3 months) No signs of active cardiovascular disease, liver or kidney malfunction  Exclusion Criteria:  Type 2 diabetes Patients with congestive heart failure and and/or severe renal and or liver insufficiency Uncontrolled hypertension Any contra-indication for MRI scanning Alcohol consumption of >3 servings per day for man and >2 servings per day for woman Smoking Unstable body weight (weight gain or loss > 5kg in the last 3 months) Engagement in structured exercise activities > 2 hours a week Previous enrolment in a clinical study with an investigational product during the last 3 months or as judged by the Investigator which would possibly hamper our study results Medication use known to hamper subject's safety during the study procedures Subjects who do not want to be informed about unexpected medical findings Use of food supplements containing NR or Resveratrol (similar working mechanisms)