Fasting ENHANCE Pilot Study

Grounded in the principles of geroscience, the proposed Fasting ENHANCE study will test whether a time restricted eating (TRE) regimen can improve cognitive function and other aspects of successful aging in a safe and sustainable manner in at risk overweight older adults. Specifically, this study will evaluate whether TRE can improve cognitive and physical function, as well as self-reported sleep, mood, and quality of life, in overweight, older adults (age \> 65 years) who are at high risk of cognitive decline due to self-reported cognitive difficulties. Eligible participants will be assigned to either a TRE intervention, in which they will be instructed to fast for a target of 16 hours per day, or a successful aging (SA) comparison group for a 24-week period.

During the past century, persons aged \>70 years represented the fastest growing segment of the US population with the life expectancy of older Americans steadily increasing, until the onset of COVID-19 in 2020. Unfortunately, the increase in lifespan has not been accompanied by an increase in health-span, which is the time-period in which a person is healthy and functionally independent. Rather, the aging population has been accompanied by an increase in the number of individuals living with chronic metabolic and neurocognitive disease conditions, including obesity, metabolic syndrome, and Alzheimer's disease and Related Disorders (ADRD). Moreover, poor metabolic health appears to be a risk factor for accelerated brain aging; therefore improving metabolic health may represent a strategy to improve long-term brain health.

Although age-related biological and metabolic changes clearly have a role in the development of chronic health conditions and risk for ADRD, a growing body of research indicates lifestyle factors contribute to modifiable patho-physiological states that precede the development of many age-related chronic health conditions. Specifically, over-nutrition, sedentary lifestyle, and poor sleep habits have been directly linked with metabolic diseases, as well as cognitive decline and development of ADRD in later life.

Our work and that of others has demonstrated that the rate of functional decline among older adults is highly influenced by biological and metabolic changes during aging, which are largely affected by lifestyle factors, namely dietary intake, sleep, and physical activity levels. Specifically, the investigators have shown that intermittent fasting (IF) regimens, particularly time restricted eating (TRE), can have positive effects on biological, metabolic, and functional health markers in middle-aged and older adults, similar to that of calorie restriction. These observations raise the possibility that interventions targeting the fundamental biology of human aging have the potential to delay, if not prevent, the onset of aging-associated conditions, such as ADRD. The unprecedented growth of the aging population has created an urgent need for promising interventions that can preserve older adult's capacity to live independently and function well.

The scientific premise of this proposal is that a time-restricted eating intervention can target the cellular and metabolic alterations that underlie age-related metabolic and neurocognitive disease conditions and thereby extend health-span in the growing population of older adults who reported subjective cognitive decline.

Eligibility Criteria:
Inclusion Criteria:

* Age ≥ 65 years;
* Body Mass Index (BMI \> 25 kg/m2)
* Normal age-, gender-, and education-adjusted performance on TICS-M (Telephone Interview for Cognitive Status)
* Responds yes to questions 1 (memory worse), 2 (word finding difficulties) or 3 (planning/organization difficulties) on the Subjective Cognitive Decline Questionnaire
* Reports onset of cognitive difficulties in past five years
* Reports they believe they are worse than others their age OR they have talked to a clinician 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, degenerative neurologic disease (e.g., Parkinson's Disease, multiple sclerosis, ALS)
* Abnormal laboratory markers (e.g., renal or liver abnormalities, elevated potassium levels, or hemoglobin and hematocrit below the lower limit of normal) as determined by study physician.
* Significant cognitive impairment, defined as a scores below the cutoff for dementia on 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 a physician;
* Other significant co-morbid disease (e.g. renal failure on hemodialysis) or severe psychiatric 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 use is 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 more than 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 or significantly 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 or diastolic 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 or heart 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 food at least 12 hours apart)
* Participating in another clinical trial or has received an investigational product within 30 days prior to screening/enrollment
* Any condition that in the opinion of the investigator would impair ability to participate in the trial.