The main objective of the study is to investigate if 6 months resveratrol supplementation can improve glucose tolerance in overweight/obese individuals. As secondary objectives we want to investigate whether resting energy metabolism, intra-hepatic lipid content, physical performance, body composition and quality of life change by 6 months resveratrol supplementation in these individuals.

Inclusion Criteria:

• Men aged 40-70 years and postmenopausal women aged 50-70 years
• BMI: 27-35 kg/m2
• Stable dietary habits: no weight gain or loss > 5kg in the last three months
• Willingness to limit consumption of resveratrol-containing food products and willingness to refrain from using resveratrol containing supplements
• Subjects will only be included when the dependent medical doctor of this study approves participation after evaluating data obtained during screening

Exclusion Criteria:

• Uncontrolled hypertension
• HbA1c > 6.5%
• Previously diagnosed with type 2 diabetes
• Medication use known to interfere with glucose homeostasis/metabolism
• Current alcohol consumption > 20 grams alcohol/day
• Subjects who do not want to be informed about unexpected medical findings during the screening /study, or do not wish that their physician is informed, cannot participate in the study.
• Participation in another biomedical study within 1 month before the start of the intervention
• Any condition, disease or abnormal laboratory test result that, in the opinion of the Investigator, would interfere with the study outcome, affect trial participation or put the subject at undue risk