White Adipose Tissue Clocks and High Calorie Feeding

Inclusion criteria

• males and females aged 20-35 yr;
• BMI 25-35 kg/m2 and weight stable (±2kg in past 2mo);
• non-smoker;
• sedentary to moderately active (≤3 days of exercise per week ≤30 min of exercise per session);
• sleeping pattern of >7 hours to 9.25 hrs of sleep/night.
• subjects will be asked to identify themselves as regular consumers of 3 balanced meals per day by answering the question: "Do you eat breakfast, lunch, and dinner on ≥ 5 days per week?"

Exclusion criteria

• Smoker (current or within the previous 3 months);
• Use any medication that could affect lipid metabolism, insulin signaling, or sleep;
• Pregnant women will not be enrolled in the study;
• Have a job that involves shift work;
• Dwelling below Denver altitude (1,600 m) a year prior to testing;
• Travel across more than one time zone 3 wk before a study;
• chronic health conditions such as diabetes, hyper or hypothyroidism, renal or liver disease, anemia, or cancer;
• Regularly go to sleep after midnight;

o Subjects will be excluded if they are identified as having night eating syndrome (at least 25% of food intake is consumed after the evening meal and/or at least two episodes of nocturnal eating per week);

• Allergy to lidocaine or similar compound;
• Have one or more of the following out-of-range values measured on a fasting blood sample:

• glucose > 110 mg/dl,
• thyroid stimulating hormone <0.5 or >5.0 µU/ml.
• Subjects who may be:

• anemic (hemoglobin < 14.5 g/dl men, <12.3 g/dl women ),
• have abnormal liver function tests (alanine amino transferase > 47 U/l, aspartate aminotransferase, > 47 U/l, alkaline phosphatase <39 or >117 U/l) or creatinine (>1.1 mg/dl).