The Time-Restricted Intake of Meals Study

Inclusion Criteria:

- Prediabetes defined by HbA1c 5.7-6.4%, or type 2 diabetes with HbA1c 6.5-6.9%

- Class I-III obesity (BMI 30-39.9 kg/m2)

- If on medications for hypertension, stable regimen for at least past 6 months

- Willingness to adjust timing of feeding

- Willingness and ability to eat study diet and nothing else during run-in and
intervention

- Willingness to complete measurement procedures

Exclusion Criteria:

- Moderate to severe obstructive sleep apnea

- Shift work;

- Other sleep/circadian disorders: e.g., circadian phase delay or phase advance;
restless legs syndrome, insomnia, narcolepsy, habitual sleep <6 hours/night

- Routinely ate within compressed time window in the past year (e.g., routinely eats all
food within an 10-hour or narrower window, follows an intermittent fasting protocol)

- Renal dysfunction (estimated Glomerular Filtration Rate (GFR) <30 using the simplified
Chronic Kidney Disease (CKD) Epidemiology Collaboration (EPI) equation 34)

- Use of glucose-lowering medications, weight loss medications, medications for sleep
disorders (sedative/hypnotic drugs, stimulants), lithium, systemic corticosteroids,
diuretics, blood thinners requiring regular monitoring (e.g. warfarin), anti-psychotic
drugs and antiretroviral therapy

- Body weight >400 pounds (limitation of facility scales)

- >1 drink per day of alcohol

- Active substance use disorder or significant psychiatric/psychologic disorder that
would interfere with participation

- Significant food allergies, preferences, intolerances, or dietary supplements that
would interfere with diet adherence

- Weight loss or gain of ≥5% during past 6 months

- Pregnant, planning to become pregnant, or breastfeeding

- Planning to start a weight loss program

- Planning to leave the area prior to end of study

- Current participation in another clinical trial

- Cancer diagnosis requiring active treatment in past two years or planned treatment
(with exception of localized non-melanoma skin cancer)

- Active inflammatory bowel disease, malabsorption, or history of major gastrointestinal
surgery involving bowel resection

- Myocardial infarction or stroke in past 6 months

- Prior bariatric surgery

- Any serious illness that would interfere with participation

- Other conditions or situations at the discretion of the PI