The Healthy Heroes Study

Participants will be randomly assigned to a control group of behavioral nutrition counseling
(standard of care) or the intervention group of standard of care with the addition of
adopting a 10 hour eating window for one year (TRF). For the first 3 months of intervention,
participants will be monitored closely by the research team. For the following 9 months,
participants will be in a self-monitored intervention period. Investigators will evaluate the
impact of TRF on blood glucose levels, biomarkers, sleep/mood, and weight loss. These
assessments will be made at baseline, at the end of the 12-week monitored intervention
period, and every 3 months (months 6, 9, and 12) during the self-monitored intervention
period for one year. Food/drink intake, activity, and sleep will be monitored with the
smartphone myCircadianClock application ("mCC app") throughout the study. A glucose monitor,
a wrist-worn actigraphy device, and questionnaires will also be used during the study.

Inclusion Criteria:

- Firefighter or work a 24-hr shift schedule with San Diego Fire and Rescue

- Age: 21-65 years

- Own a smartphone (Apple or Android Operating System)

- If participants are on cardiovascular medications (HMG-CoA reductase inhibitors
(statins), other lipid modifying drugs (including over the counter drugs such as red
yeast rice and fish oil), anti-hypertensive, anti-diabetes drugs), no dose adjustments
will be allowed during the study period

Exclusion Criteria:

- Insulin-dependent diabetes mellitus

- Presence of acute chronic inflammatory or autoimmune disease (defined by acute
symptoms or C-reactive protein >10 mg/L), malabsorption syndromes, liver disease, or
kidney disease (stage 3 or greater)

- Uncontrolled thyroid disease

- Intake of drugs likely to interfere with study endpoints, including corticosteroids,
anabolic steroids, anti-psychotics, antiretroviral drugs, and immunosuppressive drugs
(within 3 months of starting the study)

- Presence or recent history of anemia (hematocrit <33% within 3 months of starting the
study)

- History of bariatric surgery

- Pregnant or breast-feeding women

- Current or recent (within 12 months of starting the study) pregnancy or breastfeeding,
or intention of becoming pregnant in the next 6 months

- Any cancer other than non-melanoma skin cancer in the last 3 years

- On a special or prescribed diet for other reasons (e.g. Celiac disease)

- Depression determined by the Beck Depression Inventory (BDI)

- Planned international travel during study period

- Insufficient logging on the mCC app (does not log at least 2 entries a day for 10 of
14 days) during baseline will exclude from being randomized into the intervention
period