Please select the eligibility criteria that correspond to the clinical trial below.
Title: Time Restricted Feeding and Metabolic Rhythms
Brief Summary: Current guidelines for the prevention and treatment of obesity focus on caloric restriction diets and increasing physical activity, but long-term compliance to these strategies is poor. The timing of meal intake relative to the light-dark and sleep-wake cycle is rarely considered in metabolic health; and modifying meal timing is likely easier to implement in daily life than reducing caloric intake and/or increasing physical activity. This project will test whether restricting the timing of energy intake to a short-defined period during wakefulness can be used to improve fuel utilization patterns and enhance circadian rhythms in metabolic tissues to optimize health.


Options:
A: Inclusion Criteria:

* Men and women with overweight and class I obesity (N=12, Age=20-50 years; BMI 25-35 kg/m2)
* Low physical activity level (≤150 min/wk of moderate-to-vigorous activity);
* For Females- Not currently pregnant or lactating and not pregnant within the past 6 months
* Habitually consume food over a window of \>12 h/day;
* Pass a medical and physical screening performed by the study physician.
* Report a habitual, regular sleep-wake cycle for the month preceding screening that involved going to bed between 2200 and 0100h and getting up between 0600 and 0900 h with \>7 h and \<9.25 h in bed;
* Agree to eat control diets at imposed times for 1 week prior to the inpatient CTRC visits;
* Agree to keep a regular sleep/wake schedule for the duration of the study
* Possess a smart phone to install and utilize the meal timing application.

Exclusion Criteria:

* Subjects must not be currently participating in another research study that would influence their safe participation in this study. For example, subjects must not be participating in a research study in which they ingest experimental medication, or which involves blood samples, since both of these factors could increase risk of participation;
* Being considered unsafe to participate as determined by the study physician;
* Taking medications affecting weight, triglycerides, energy intake/energy expenditure, or sleep in the last 3 months;
* Having abnormal blood chemistry and/or hematology as deemed significant by the study physician;

  o Have one or more of the following out-of-range values measured on a fasting blood sample: glucose \> 126 mg/dl, HbA1c \> 6.5%, thyroid stimulating hormone \<0.5 or \>5.0 uU/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)
* Significant abnormality in clinical laboratory values
* Ever having a history of systemic, psychiatric, neurological disease, or drug and alcohol abuse;
* History of cardiovascular disease, diabetes, uncontrolled hypertension, untreated thyroid, renal, hepatic diseases, dyslipidemia or any other medical condition affecting weight or lipid metabolism;
* Score \> 18 on Beck Depression Index (BDI) will require further assessment by the study physician to determine if it is appropriate for the subject to participate in the study;
* Use of a continuous positive airway pressure (CPAP) device for the treatment of obstructive sleep apnea (OSA). A score of \>10 on the Epworth sleepiness scale or \>5 on the Pittsburgh Sleep Quality Index will require further assessment by the study physician to determine if it is appropriate for the subject to participate in the study;
* Being positive for human immunodeficiency virus or hepatitis B or C;
* Being a smoker or having been a smoker in the previous 6 months;
* Abnormal eating patterns identified by registered dietician interview (dietary fat\<15%, dietary fat\>45%, dietary protein \>30%);
* Working night shifts;
* 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);
* Traveling \> 2 time zones 2 weeks prior to an inpatient CTRC study visit;
* Currently participating in any formal weight loss or physical activity programs or clinical trials.
* Having a clinically significant allergy (e.g., to food stuffs such as shellfish, peanuts);
* Celiac disease or known sensitivity to gluten (the metabolic kitchen is not gluten free certified and cannot accommodate this dietary restriction)
B: Inclusion Criteria:

* Ability to provide informed consent
* Baseline brachial flow-mediated dilation (FMD) \< 6%Δ (rationale: non-invasive screening to ensure exclusion of subjects with exceptionally high baseline endothelial function.
* Ability to perform motor and cognitive tests (e.g., can rise from a chair, walk for 2 min, climb 10 stairs)
* Women will be confirmed as postmenopausal (either natural or surgical) based on cessation of menses for \>1 year.

Exclusion Criteria:

* Ages \<55 years or ≥80 years
* Occupation that requires night-shift work or abnormal hours that would disrupt eating schedule
* Dietary habit of regularly skipping meals, already eating within a \~10 hour window, or any other form of restrictive eating.
* Unable to adhere to an 8 hour eating window for the length of the study period
* Participation in regular vigorous aerobic/endurance exercise (\>3 vigorous bouts/week)
* Not weight stable in the prior 3 months (\>2 kg weight change).
* Body mass index (BMI) \>40 kg/m\^2 (rationale: vascular function measurements can be inaccurate in severely obese subjects)
* Current smoking
* Diagnosis of a chronic clinical disease (e.g., coronary artery/peripheral artery/cerebrovascular diseases, diabetes, chronic kidney disease requiring dialysis, neurological disorders or diseases that may affect motor/cognitive functions \[multiple sclerosis, Parkinson's disease, polio, Alzheimer's disease, dementia or other brain diseases of aging\]), except hypertension and hyperlipidemia.
* Having unstable angina, acute myocardial infarction, coronary angioplasty, or aorto- coronary bypass surgery as defined by the occurrence of an event, symptom, surgery, or change in medication and/or dosage within 3 months prior to enrollment.
* Having thyroid disease that is not controlled by medications or \<3 month's use of a particular medication and/or dosage (rationale: uncontrolled thyroid diseases are associated with alterations in vascular function).
* Having past or present alcohol dependence or abuse, as defined by the American Psychiatry Association, Diagnostic and Statistical Manual of Mental Disorders
C: Inclusion Criteria:

* Are male
* Overweight: Have a body mass index between 25 and 50 kg/m\^2 inclusive (a number calculated from height and weight)
* Are 35-70 years of age
* Have a hemoglobin A1C between 5.5 - 6.4% or prior medical indication of prediabetes
* Have a blood sugar level between 140 and 199 mg/dL two hours after drinking a sugary solution (OGTT)
* Have been eating dinner at least 8.5 hours after eating breakfast at least 90% of the time during the past year
* Have not fasted (go for a day without any food) more than 12 days total during the past year
* Be willing to eat most meals at Pennington Biomedical and/or under supervision
* Not eat any food other than that served by Pennington Biomedical
* Not drink any alcohol, juice, or other beverages that have calories other than what is served by Pennington Biomedical
* Keep water and no-calorie drinks like tea or diet soda the same during both of the timed eating periods
* Be willing to eat your meals according to the fixed schedules

Exclusion Criteria:

* Have diabetes or are on anti-diabetes medication
* Have evidence of cardiovascular disease
* Suffer from significant cardiovascular, renal (kidney), cardiac (heart), liver, lung or nervous system disease
* Evidence of significant gastrointestinal issues or surgery that impacts nutrient absorption
* Regularly use medications such as steroids, beta blockers, and adrenergic-stimulating agents
* Are on any regular medicine that has not had the same dose for 1 month or longer
* Have a clinically significant abnormality as measured by a blood test
* Regularly drink alcohol (more than 2 servings per day)
* Have to do any kind of heavy physical activity
* Currently perform overnight shift work more than one day a week
* Are not able to eat only the food served to you by Pennington Biomedical, while in the study
* Are not able to stop drinking alcohol or other drinks with calories (e.g., soda, juice) other than what is served to you by Pennington Biomedical, while in the study
D: Inclusion Criteria:

* Men and women
* Age 30-70 years
* Language: English or Spanish
* At least 3 features of the NCEP ATP-III metabolic syndrome

Exclusion Criteria:

* Diabetes
* Established CVD
* Uncontrolled hypertension (systolic BP \>160 and diastolic BP \>100 mm Hg)
* Established liver disease
* Renal insufficiency
* Psychiatric illness
* Chronic substance abuse within the past 5 years
* Chronic obstructive pulmonary disease or severe asthma.

Answer: A