Fasting ENHANCE Pilot Study

Inclusion Criteria:

• Age ≥ 65 years;

• Body Mass Index (BMI > 25 kg/m2)

• Normal age-, gender-, and education-adjusted performance on TICS-M (TelephoneInterview for Cognitive Status)

• Responds yes to questions 1 (memory worse), 2 (word finding difficulties) or 3 (planning/organization difficulties) on the Subjective Cognitive DeclineQuestionnaire

• Reports onset of cognitive difficulties in past five years

• Reports they believe they are worse than others their age OR they have talked to aclinician about it.

• Provides informed consent and willing to be randomized to either intervention group.

Exclusion Criteria:

• Failure to provide informed consent;

• Recent History or clinical manifestation of cardiovascular disease, diabetes,cholelithiasis, liver or renal disease, cancer, or progressive, degenerativeneurologic disease (e.g., Parkinson's Disease, multiple sclerosis, ALS)

• Abnormal laboratory markers (e.g., renal or liver abnormalities, elevated potassiumlevels, or hemoglobin and hematocrit below the lower limit of normal) as determinedby study physician.

• Significant cognitive impairment, defined as a scores below the cutoff for dementiaon TICS-M

• Severe rheumatologic or orthopedic diseases (e.g., awaiting joint replacement,active inflammatory disease);

• Terminal illness with life expectancy less than 12 months, as determined by aphysician;

• Other significant co-morbid disease (e.g. renal failure on hemodialysis) or severepsychiatric disorder (e.g. bipolar, schizophrenia);

• Current use of anabolic medications (i.e., growth hormones or testosterone),antidepressant medications, antipsychotic agents, monoamine oxidase inhibitors,anticholinesterase inhibitors (i.e., Aricept), anticoagulant therapies (aspirin useis permitted), or antibiotics;

• Excessive alcohol use (>14 drinks per week);

• History of drug or alcohol abuse (i.e., more than 5 drinks/day for males or morethan 4 drinks/day for females);

• Planning to permanently leave the area in the next year;

• History of pulmonary disease, pneumonitis or interstitial lung disease;

• Current smoker or less than 3 years quit;

• Creatinine clearance < 30 ml/minute by estimated Glomerular Filtration Rate (eGFR);

• Fasting >12 hours per day

• Actively trying to lose weight by participating in formal weight loss program orsignificantly restricting calorie intake or weight loss > 5 lbs in the past month

• Resting heart rate of >120 beats per minute, systolic blood pressure > 180 mmHg ordiastolic blood pressure of > 100 mmHg

• Unstable angina, heart attack or stroke in the past 3 months

• Continuous use of supplemental oxygen to manage a chronic pulmonary condition orheart failure

• Rheumatoid arthritis, Parkinson's disease or currently on dialysis

• Insulin dependent diabetes mellitus

• Taking medications that preclude fasting for 16 hours (e.g. must be taken with foodat least 12 hours apart)

• Participating in another clinical trial or has received an investigational productwithin 30 days prior to screening/enrollment

• Any condition that in the opinion of the investigator would impair ability toparticipate in the trial.