Restoring 24-hour Substrate Rhythmicity to Improve Glycemic Control by Timing of Lifestyle Factors

Inclusion Criteria: * Pre-diabetes: * Fasting plasma glucose: 6.1 to 6.9 mmol/L or * 2-hour plasma glucose post 75g OGTT: 7.8 to 11.0 mmol/L and * HbA1c: 6.0 to 6.4% * or Insulin resistant: glucose clearance rate ≤ 360 ml/kg/min as determined using the Oral Glucose Insulin Sensitivity Index at Time 120 min. * BMI \> 25 kg/m2 * To be willing and able to adhere to the specifications of the protocol; * To have signed an informed consent document indicating that they understood the purpose of and procedures required for the study and were willing to participate in the study. Exclusion Criteria: * overt cardiovascular disease as assessed by medical history, physical exam, and abnormal ECG * Treatment with any drug known to affect lipid or carbohydrate metabolism, except statins (to be stopped 3 weeks prior to study A), metformin or anti-hypertensive drugs (to be stopped 7 days prior to the studies); * presence of liver or renal disease other than uncomplicated NASH or mild isolated proteinuria; uncontrolled thyroid disorder; * Uncontrolled severe hypertension, systolic pressure ≥ 180 mm Hg or diastolic pressure ≥ 110 mm Hg; * History of ischemic heart disease, tachyarrhythmia, QT interval prolongation, risk factors for torsade de pointes (eg hypokalemia), or taking any medication known to prolong the QT interval; * History of serious gastrointestinal disorders (malabsorption, peptic ulcer, gastroesophageal reflux requiring surgery, etc.); * Presence of a pacemaker; * Having undergone a PET study or CT scan in the past year; * Any contraindication to stopping statins for 3 months and stopping an anti-hypertensive medication and metformin for 7 days; * smoking (\>1 cigarette/day) and/or consumption of \>2 alcoholic beverages per day; * No blood donation two month prior the study; * prior history or current fasting plasma cholesterol level \> 7 mmol/l or fasting TG \> 6 mmol/l.