Overview
In a randomized controlled trial, the investigators intend to measure the health impact of time restricted eating (TRE) in patients with metabolic syndrome (with elevated blood pressure and at least 2 of the following: increased waist circumference, abnormal cholesterol levels, elevated triglycerides, and elevated fasting glucose levels), who habitually eat more than 12 hours every day. Patients will be randomly assigned to a control group (standard of care) or intervention group (TRE).
Description
Circadian rhythms optimize nutrient homeostasis by orchestrating catabolic and anabolic metabolism to appropriate times of the 24 hour day. Chronic circadian rhythm disruption predisposes individuals to metabolic diseases including obesity and type 2 diabetes. Conversely, maintaining a daily rhythm of feeding and fasting cycles sustains a robust circadian rhythm which improves cellular bioenergetics and results in improved metabolism. Time-restricted eating (TRE) is a specific feeding-fasting pattern in which feeding is restricted to 8-12 hours a day.
Over the 54-week duration of the study, participants will be required to use a smartphone application (myCircadianClock, developed by the Salk Institute) to log all food and beverage intake. Investigators will measure height, weight, waist circumference, and blood pressure throughout the study. Blood tests will be done after an overnight fast to check HbA1C, glucose, insulin, lipids, and an NMR lipoprotein profile. Blood sugar will also be monitored continuously using a continuous glucose monitor (CGM) worn for 2 weeks at the beginning of the study, at 6 months, and at 12 months (end of the study). At these same three timepoints, participants will also wear a wrist-worn actigraphy device (actiwatch) to track physical activity and sleep patterns. Body composition will be measured using a dual energy X-ray absorptiometry (DEXA) scan, and an oral glucose tolerance test (OGTT) will be performed to assess how the body responds to sugar.
Eligibility
Inclusion criteria:
- Age: 18-75 years
- HbA1c: 5.7% to 7.0%
- Metabolic syndrome (must meet 3 criteria): Elevated systolic blood pressure ≥ 130 mm
Hg or diastolic blood pressure ≥ 85 mm Hg (required) and 2 of the following:
- Elevated waist circumference:
- In Asians: ≥ 90 cm in men, ≥80 cm in women
- In all other races: ≥ 102 cm in men, ≥ 88 cm in women
- Fasting plasma triglycerides ≥ 150 mg/dL, or on drug treatment for elevated
triglycerides
- Reduced High-density lipoprotein (HDL)- cholesterol < 40 mg/dL in males or < 50 mg/dL in females, or drug treatment for reduced HDL-cholesterol
- Fasting glucose ≥ 100 mg/dL
- Elevated waist circumference:
- Own a smartphone (Apple iOS or Android OS)
- Baseline eating period ≥12 hour/day
- Patients on a stable dose of cardiovascular medications (HMG CoA reductase inhibitors (statins), metformin, other lipid-modifying drugs (including over-the-counter drugs such as red yeast rice and fish oil), anti-hypertensive drugs, GLP-1R agonists and SGLT2 inhibitors) for at least 3 months are allowed.
Exclusion Criteria:
- Use of sulfonylurea or insulin.
- HbA1C > 7.0%
- Pregnant or breastfeeding. Anyone of reproductive age will receive pregnancy test prior to DXA scan.
- Caregiver for a dependent requiring frequent nocturnal care / sleep interruptions.
- Shift workers with variable (e.g. nocturnal) hours.
- Frequent travel to different time zones during the study period.
- Active tobacco use or illicit drug use or history of treatment for alcohol abuse.
- History of major adverse cardiovascular event within the past year (acute coronary syndrome, percutaneous coronary intervention, coronary artery bypass graft surgery, hospitalization for congestive heart failure, stroke/transient ischemic attack).
- Uncontrolled arrhythmia (i.e. rate -controlled atrial fibrillation / atrial flutter are not exclusion criteria)
- History of thyroid disease requiring dose titration of thyroid replacement medication(s) within the past 3 months (i.e. hypothyroidism on a stable dose of thyroid replacement therapy is not an exclusion).
- History of adrenal disease.
- History of malignancy undergoing active treatment, except non-melanoma skin cancer.
- Known history of type 1 diabetes.
- History of an eating disorder.
- History of cirrhosis.
- History of stage 4 or 5 chronic kidney disease or requiring dialysis.
- Currently enrolled in a weight-loss or weight-management program.
- On a special or prescribed diet for other reasons (e.g. Celiac disease).
- Uncontrolled psychiatric disorder (including history of hospitalization for psychiatric illness).