NCT06169137Completed
Pilot Study of Isocaloric Time Restricted Eating on Ketone Metabolism and Immunoregulation
Source: ClinicalTrials.gov · Last updated 9 Jul 2026
Brief summary (registry, in English)
Background: Time restricted eating (TRE) is a form of fasting in which a person eats only during a set window of time, which is usually between 4 and 10 hours each day. Researchers want to know more about how TRE may affect health. Objective: To learn how TRE affects women with different body sizes. Eligibility: Healthy women aged 18 to 50 years. Design: Participants will have 2 visits: 1 screening visit and one 5-day stay in the clinic. Participants will fast before both visits. They will have a physical exam with blood tests. They will talk to a nutritionist about the foods they eat. They will lay under a clear hood for up to 45 minutes during a test that measures how many calories they burn while resting. Participants will keep a food diary for up to 7 days before their clinic stay. They will apply a continuous glucose monitor the day before they go to the clinic. This is a device that attaches to the skin of the stomach. They will wear this device throughout their clinic stay. All meals will be provided during the clinic stay. Participants will follow TRE on 3 days. They will answer survey questions and have tests during their stay, including: * DXA (dual energy X-ray absorptiometry) scan. Participants will lie on a padded table. Their body will be scanned to measure how much muscle, bone, fat, and other tissues they have. * Stable isotope tracer study. Small amounts of sugar and other substances will be given through a tube attached to a needle inserted into a vein in the arm. Blood samples will be collected.
- Status (registry)
- Completed
- Study type
- Interventional
- Enrollment
- 58 (actual)
- First submitted
- 11 Dec 2023
- Start date
- 4 Sept 2024
- Primary completion date
- 22 May 2026
- Lead sponsor
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
- Diseases
- Obesity
- NCT number
- NCT06169137
What you commit to
- Study type: Interventional
- Participants enrolled: 58
- From 4 Sept 2024 to the primary completion date, 22 May 2026
- 1 site in 1 country
- Visits and tests: ask the trial team, the registry does not list them
Built from the registry fields of ClinicalTrials.gov. It describes the study, not your situation.
Who cannot take part
Copied verbatim from ClinicalTrials.gov and grouped by topic. Only the trial team decides who can take part.
Prior treatment
- Current use of antihyperglycemic medications, systemic steroids, adrenergic-stimulating agents, or medications affecting sleep, circadian rhythms, or metabolism which affect parameters under investigation (examples include oral contraceptives, anti-diabetic agents, nicotinamide riboside, tryptophan, vitamin B3 supplements)
- Unstable weight with more than 5% body weight change in last previous 3 months
- Current smoker or regular tobacco use, vaping, or other forms of nicotine within prior 3 months
- This study will recruit only women. The study design was informed by our Protocol NCT04728165 which investigates an identical 6:18h TRE intervention in males who are healthy and those with psoriasis. Based on our pilot data in men, the current study is needed to test our hypothesis in women. This study in women is a critical next step to replicate the findings in women and to understand sex-specific differences in TRE response and ketone metabolism.
Other illness
- Diagnosis/treatment for immune/inflammatory disorder or other metabolic conditions that would interfere with study parameters, including diabetes, chronic kidney, chronic liver disease, history of hypoglycemia, and thyroid disease (with the exception of chronic controlled hypothyroidism as measured by TSH within normal limits)
- History of an eating disorder by self-report or medical history
- Food allergies/intolerances or dietary patterns that would prohibit consumption of metabolic diet
Other
- An individual who meets any of the following criteria will be excluded from participation in this study:
- Caffeine consumption in excess of approximately 300 mg (approximately three 8-oz cups of coffee) daily
- Factors that affect circadian rhythms including individuals who perform overnight shift work, report irregular sleep and/or eating schedules, and who regularly fast for more than 15 hours/day
- Inability to provide informed consent
- Pregnancy or lactation
- Engaged in competitive sports training and/ or unwilling to comply with exercise regimen in this protocol.
- Consumption of more than 3 servings of alcohol daily
Criteria the registry did not label
- INCLUSION CRITERIA:
- In order to be eligible to participate in this study, an individual must meet all of the following criteria:
- Stated willingness to comply with all study procedures and availability for the duration of the study
- Women between ages 18-50 years who are premenopausal (defined as regular menses and/or FSH \<ULN)
- BMI of 18-24.9 or \>=30 kg/m\^2
- In good general health as evidenced by medical history and/or screening laboratory evaluation.
- Agreement to adhere to Lifestyle Considerations throughout study duration
Age in the registry: 18 years to 50 years · Sex: Female · Does not accept healthy volunteers
Sites (1)
Sites in registry order. Pick your city on the disease page to sort them by distance.
| Site | City | Country | Site status |
|---|---|---|---|
| National Institutes of Health Clinical Center Coordinator of this site? Confirm its status | Bethesda | United States | Unknown status |
Related publications
This page is information, not medical advice. Discuss any trial with your doctor.