Please select the eligibility criteria that correspond to the clinical trial below.
Title: Intermittent Fasting for Metabolic Health, Does Meal Timing Matter?
Brief Summary: Obesity is a serious medical condition, the adverse consequences of which include increased risk of cardiovascular disease, diabetes mellitus, reduced fertility and cancer. The economic cost of obesity was placed at $58 billion dollars in Australia in 2008. Studies in mice and non-human primates have shown that moderate caloric restriction (CR) increases lifespan and reduces the incidence of cardiovascular disease, cancer, and type 2 diabetes. Reduced risk of chronic diseases is also observed in humans following CR. However, daily CR is difficult to maintain long term, since the body defends against weight loss by inducing "metabolic adaptation" and altering the hormonal appetite response. An emerging number of studies are examining the effects of limiting food intake to prescribed time periods per day, or every other day. Intermittent, or time restricted feeding describes a dieting approach where food is available ad libitum, however only for a limited period of time (i.e. 3-12 hours). This study will examine the effects of fasting for 15h/day and eating for 9-h per day on glycemic control and metabolic health. This study will build on the existing knowledge base in humans as to whether meal timing, rather than caloric restriction per se, is important to provide the stimulus required to improve metabolic health and reduce risk of chronic disease. Moreover, it will examine whether restricting feeding to later in the day is of lesser benefit to health.


Options:
A: Inclusion Criteria:

* Waist circumference \>102cm
* BMI \>30 kg/m2

Exclusion Criteria:

* Personal history of cardiovascular disease, diabetes, eating disorders
* use of medications which may affect energy metabolism, gastrointestinal function, body weight or appetite (e.g. domperidone and cisapride, anticholinergic drugs, androgenic medications, metoclopramide, orlistat, diuretic medications
* use of prescribed glucose-lowering/antidiabetic medication
* recent weight change in past 3 months,or does not habitually eat breakfast
* uncontrolled asthma, current fever, upper respiratory infections
* current intake of \> 140g alcohol/week
* current smokers of cigarettes/cigars/marijuana
* current intake of any illicit substance
* experience claustrophobia in confined spaces
* has donated blood within past 3-months
* unable to comprehend study protocol
B: Inclusion criteria. Adult subjects meeting the following criteria will be eligible to participate:

* Age between 18 to 65 years old
* BMI between 25.0 and 39.9 kg/m2
* Previously sedentary (\<60 minutes/week of light activity corresponding to 2.5 to 4.0 metabolic equivalents (METs) for the 3 months prior to the study)

Exclusion criteria. Subjects excluded from participating in the study include those who:

* Have a history cardiovascular disease (prior angina, myocardial infarction or stroke)
* Are diabetic (fasting blood glucose \> 126 mg/dl)
* Have a history of psychiatric disorders and/or eating disorders
* Are taking anti-depressant or anti-anxiety medications
* Are taking drugs that affect study outcomes (weight loss, lipid-lowering, or blood pressure drugs)
* Are not weight stable for 3 months prior to the beginning of study (weight gain or loss \> 4 kg)
* Are not able to keep a food diary or activity log for 7 consecutive days during screening
* Are perimenopausal or have an irregular menstrual cycle (menses that does not appear every 27-32 days)
* Are claustrophobic or have implanted electrical devices (cardiac pacemaker or a neurostimulator)
* Are pregnant, or trying to become pregnant
* Are smokers
C: Inclusion Criteria:

* Male or female
* Body mass index (BMI) between 30.0 and 40 kg/m2
* Age between 25 and 65 years
* Sedentary (light exercise less than 1 h per week) or moderately active (moderate exercise 1 to 2 h per week)
* Weight stable for \>3 months prior to the beginning of the study (gain or loss \<4 kg)
* Able to give written informed consent

Exclusion Criteria:

* Smoker
* Diabetic
* History of cardiovascular disease (myocardial infarction or stroke)
* Taking weight loss medications
* History of eating disorders
* Night-shift workers
* Perimenopausal
* Pregnant or trying to become pregnant
D: Inclusion Criteria:

* Competitive runners who have been actively training for 3 or more years
* Weigh a minimum of 110 lbs
* Training 4-6 times per week and run a minimum of 20 miles per week
* Competed in a race within past 12 months at a distance of 5 - 26.1 km
* Willing to repeat same monthly training protocol during two 4-week interventions
* VO2max range of 40-70 ml/kg/min

Exclusion Criteria:

* Smoker
* Take medications that have cardiovascular or metabolic effects
* Taking dietary supplements
* Following a restrictive diet including restricting calories or carbohydrates
* Evidence of an eating disorder
* Major injuries in past 3 months
* Chronic disease that affects bone health, metabolism or the cardiorespiratory system
* Present with any contra-indication to exercise testing (cardiovascular abnormalities) as evaluated by study physician

Answer: A