Inclusion Criteria:  Signed informed consent Healthy (determined by dependent physician) Man or post-menopausal woman Age between 50 - 75 years BMI ≥ 25 kg/m2 Pre-diabetes based on meeting at least one of the following criteria: impaired glucose tolerance defined as plasma glucose values ≥ 7.8 mmol/l and ≤ 11.1 mmol/l 120 minutes after glucose drink consumption during oral glucose tolerance test in screening, impaired fasting glucose defined as fasting plasma glucose ≥ 6.1 mmol/l and ≤ 6.9 mmol/l, insulin resistance defined as a glucose clearance rate ≤ 360 mL/kg/min as determined using OGIS120, HbA1c of 5.7-6.4% Regular sleeping habits (7 - 9h of daily sleep) Stable diet and weight: No weight gain or loss > 3kg in the last three months  Exclusion Criteria:  Not meeting all inclusion criteria Fasting plasma glucose ≥ 7.0 mmol/L Hemoglobin < 7.8 mmol/L Previously diagnosed with type 2 diabetes Uncontrolled hypertension In case of an abnormal electrocardiogram at rest: this will be discussed with the responsible medical doctor 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 Any contra-indication to the Equivital telemetric pill Hypomotility disorders of the gastro-intestinal tract Extreme early bird or extreme night person (score ≤30 or ≥70 on morning-eveningness questionnaire self assessment) Heavily varying sleep-wake rhythm Night shift work during last 3 months Travel across > 1 time zone in the last 3 months Frequent engagement in programmed exercise as judged by the investigator Significant food allergies/intolerance (seriously hampering study meals) Participation in another biomedical study within 1 month before the first study visit Using > 400mg caffeine daily (more than 4 cups of coffee or energy drinks) Smoking Any acute condition, exacerbation of chronic condition, or medical history that would in the investigator's opinion interfere with the study Antecubital veins that present tremendous difficulty in obtaining frequent blood draws (e.g. too small)