The TREAT Pilot is a 3 months open-label pilot study to examine the effect of restricting the duration of eating (Time Restricted EATing) in metabolically unhealthy adults with overweight or obesity. This pilot study will allow the investigator to collect preliminary data for the design of a larger study.

Disruption of the circadian rhythm, caused by aging, obesity, shift work, or prolonged daily eating duration into hours normally reserved for sleep, is a recognized risk factor for impaired metabolism and cardiovascular disease risk. Mice with disrupted clock gene have dysmetabolism. Restricting the eating window in these mice improves their metabolism.

Data will be collected to examine the feasibility and effect of a lifestyle intervention, aiming to reduce body weight in metabolically unhealthy individuals with overweight and obesity. The TREAT pilot study employs the use of mobile application to document eating behavior, when, what and how much people eat. In addition, the participants will receive reminders and complete in-person study visits to monitor their eating and sleeping schedule.

Inclusion Criteria:

• age: 45-73y old
• overweight or obesity with BMI ≥25.0 and ≤35.0 kg/m2
• pre-diabetes or diabetes only diet controlled (HbA1c <7%)
• elevated Blood Pressure (BP) 120-129/<80 mmHg or stage 1 high BP 130-139/80-89 mmHg, with clinical Atherosclerotic Cardiovascular Disease (ASCVD) or estimated 10-y Cardiovascular Disease (CVD) risk <10%
• having LDL cholesterol <150mg/dl
• no known sleep, psychiatric or food intake disorders
• in possession of a smart phone
• English-speaking
• must live in New York city geographical area and not have planned travel schedule interfering with the study

Exclusion Criteria:

• history or clinical evidence of condition that affect sleep
• significant organ system dysfunction/disease: diabetes, severe pulmonary, kidney or cardiovascular disease, and any evidence of active illness (e.g., fever)
• history of seizure disorder
• being on medications for diabetes, hypertension or dyslipidemia
• previous bariatric surgery
• history or current significant psychiatric disorder
• use dietary supplements and/or medications known to affect sleep, circadian rhythms or metabolic function
• smoking tobacco or using illegal or recreational drugs
• consume excessive alcohol (women: >14 drinks/wk; men: >21 drinks/wk)
• consume large amounts of caffeine daily (>2 cups of coffee or 8 oz caffeinated drinks per day)
• participate in intense exercise (causing heavy breathing and sweating, such as jogging) >2 d/wk for ≥35 min or moderate exercise (e.g., brisk walking) for >150 min/wk
• shift work
• extreme early and late chronotypes
• unwilling/unable to provide informed consent