Please select the eligibility criteria that correspond to the clinical trial below.
Title: The Effects of Four Weeks of Intermittent Fasting on Resting Energy Expenditure, Satiety Hormones, Body Composition, and Performance in Competitive Runners
Brief Summary: This is a cross-over intervention study designed to evaluate how four weeks of time restricted feeding (16 hours fasting and 8 hours feeding), compared to four weeks of a more traditional eating pattern (12 hours fasting and 12 hours feeding), affects resting energy expenditure, subjective and biochemical markers of satiety and hunger, body composition, cardiovascular health, substrate utilization and fitness in male competitive runners.


Options:
A: Inclusion Criteria:

* Healthy men and women (based on standard laboratory tests and a screening examination)
* 20-42 years of age
* BMI in the range 25-29.9 kg/m2
* Proportional representation of minorities in the Greater Boston Area (7 percent Black, 11 percent Hispanic, 82 percent non-Hispanic white)
* Able to accurately complete a food record
* Stage of change \>1 for weight loss and changing dietary intake
* Must have an immediate adult family member who is supportive of weight loss

Exclusion Criteria:

* Known serious disorders that affect longevity, energy metabolism, body composition and immune responsiveness, including diabetes, cancer, heart disease, cachexia, eating disorders (anorexia and bulimia and any vomiting for means of weight control), depression, alcoholism, inflammatory disorders and AIDS, and individuals taking medicine that is anticipated to influence lifespan or energy metabolism
* Abnormal kidney function as assessed by serum creatinine, BUN and urinalysis, and abnormal liver function as assessed by SGPT, SGOT alkaline phosphatase, and bilirubin, abnormal normal thyroid function as assessed by serum T4 and TSH and fasting serum glucose levels \<125 mg/dl
* Smoking, highly restrained eating, reported endurance training (participation in sports or training \>12 hours per week), alcohol intake of 14 oz. per week or more, major medical and/or psychiatric disorders, plans to have a child within 3 years (1 year for Pilot study), past childbearing (for women) within the last 2 years, or breastfeeding within the past year
* Amputees
* Have required treatment for any psychiatric disorder
* Gained or lost \>15 lb weight within the past year, or taking medications known or suspected to have an important influence on lifespan, energy metabolism, body composition or immune function
* Early death from cardiovascular diseases, cancer, or a diabetes-related illness (before the age of 45 years) in one or both of the parents
* Unable to remain in the program for at least 1 year, or unsuitable for home-based programs (including individuals reporting binge eating disorders or clinical depression, and women intending to become pregnant)
B: Inclusion Criteria:

* Aged \>35-75 years
* Waist circumference above cut-off for high risk of cardio-metabolic disease of \>102 cm in men with a Europid, Black African and Caribbean, and other ethnic background and \>88 cm in women with a Europid, Black African and Caribbean, and other ethnic background (WHO, 2008), and ≥90 cm in men and ≥80 cm in women with an Asian background (South Asian and East Asian) (Misra et al., 2009).

REFERENCES Misra A, Chowbey P, Makkar BM, Vikram NK, Wasir JS, Chadha D, et al. (2009). Consensus statement for diagnosis of obesity, abdominal obesity and the metabolic syndrome for Asian Indians and recommendations for physical activity, medical and surgical management. The Journal of the Association of Physicians of India 57: 163170.

WHO (2008). Waist circumference and waist-hip ratio: report of a WHO expert consultation. Geneva, 8-11 December 2008.

Exclusion Criteria:

* Kidney or cardiovascular disease, cancer, diabetes, gastrointestinal or chronic liver disease;
* previous bariatric surgery or other major surgery (e.g. organ transplantation);
* unable to provide written informed consent;
* have significant psychiatric disorder (e.g. schizophrenia, anxiety, panic disorder, attention deficit disorder, post-traumatic stress disorder, obsessive compulsive disorder) or uncontrolled depression;
* participated in a weight management drug trial in the previous 3 months;
* have binge eating behaviour;
* have uncontrolled epilepsy;
* alcohol or substance abuse;
* currently pregnant, lactating, or planning pregnancy within the study period;
* are using medication clinically deemed to affect metabolic rate and weight (e.g. beta blockers, corticosteroids, diuretics, etc);
* lactose intolerant.
C: 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
D: Inclusion Criteria:

1. The volunteer (male or non-pregnant female, any ethnicity) must be \>18 years of age.
2. The volunteer must either have a body mass index of 25.0-35.0 kg/m2 or the combination of a body mass index of 18.5-24.9 kg/m2 and two or more previously or currently measured symptoms of the metabolic syndrome (fasting glucose≥110 mg/dL, triglycerides≥150 mg/dL, high-density lipoprotein cholesterol\<40 mg/dL in males or \<50 mg/dL in females, systolic blood pressure≥130 mmHg or diastolic blood pressure≥85 mmHg, or waist circumference≥40 inches in males or ≥36 inches in females \[glucose and cholesterol levels may be self-reported\]).
3. The volunteer has not routinely participated in caloric restriction (deliberate limitation of caloric intake of \<80% than the FDA-recommended daily caloric intake) within the last 2 years, has not participated in extended fasting (\>12 hours at a time) for at least a year, and does not deliberately skip meals as a routine dietary practice.

Exclusion Criteria:

1. Body mass index \<18.5 or \>35 kg/m2.
2. Current active cancer treatment, treatment with immunosuppressive medications, or solid organ transplantation within 1 year.
3. Presence of immunosuppressive disease, myocardial infarction, peripheral vascular disease, or stroke within the past year.
4. Use of insulin.
5. Although it is unlikely fasting will harm the pregnant or lactating woman, the dietary restrictions placed on the participant for the duration of the study may conflict with dietary recommendations for pregnant or lactating women. Women of child bearing potential, therefore, will meet an exclusion if they become pregnant.

Answer: C