NCT06169137

Brief Summary

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.

Trial Health

77
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
150

participants targeted

Target at P75+ for not_applicable obesity

Timeline
9mo left

Started Sep 2024

Typical duration for not_applicable obesity

Geographic Reach
1 country

1 active site

Status
recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

Study Progress69%
Sep 2024Feb 2027

First Submitted

Initial submission to the registry

December 11, 2023

Completed
2 days until next milestone

First Posted

Study publicly available on registry

December 13, 2023

Completed
9 months until next milestone

Study Start

First participant enrolled

September 4, 2024

Completed
2.4 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

February 5, 2027

Expected
Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

February 5, 2027

Last Updated

August 22, 2025

Status Verified

August 20, 2025

Enrollment Period

2.4 years

First QC Date

December 11, 2023

Last Update Submit

August 21, 2025

Conditions

Keywords

DietTime Restricted EatingInflammationKetone Bodies

Outcome Measures

Primary Outcomes (2)

  • Change in ketone body (beta hydroxybutyrate) rate of appearance (Ra)

    Within subject difference in ketone body (beta hydroxybutyrate) rate of appearance (Ra) after 3 days of 6-hr TRE compared to a 12-hr eating window regimen

    Day 0, Day 3

  • Change in CD4+ T cell responsiveness (Th17 polarization)

    Within subject difference in CD4+ T cell response after 3 days of 6-hr TRE compared to a 12-hr eating window regimen

    Day 0, Day 3

Secondary Outcomes (4)

  • Change in post-absorptive glucose rate of appearance (Ra)

    Day 0, Day 3

  • Change in ketone body rate of appearance (Ra) in lean women vs women with obesity

    Day 0, Day 3

  • Change in CD4+ T cell responsiveness (Th17 polarization) in lean women vs women with obesity

    Day 0, Day 3

  • Ketone biology in isolated CD4+ T cells

    Day 0, Day 3

Study Arms (1)

Premenopausal women (lean and obese)

EXPERIMENTAL

Ages 18-50 yearsBMI 18.0-24.5 mg/k\^2 or BMI \> 30 mg/k\^2

Behavioral: Early Time-Restricted EatingBehavioral: Conventional dietary regimen (12-hr, 9:30a-9:30p)

Interventions

Participants will be provided all meals to consume within a 6-hour timeframe (9:30-3:30p)

Premenopausal women (lean and obese)

Participants will be provided all meals to consume within a 12-hour timeframe (9:30a-9:30p)

Premenopausal women (lean and obese)

Eligibility Criteria

Age18 Years - 50 Years
Sexfemale
Healthy VolunteersNo
Age GroupsAdult (18-64)

You may qualify if:

  • 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

You may not qualify if:

  • An individual who meets any of the following criteria will be excluded from participation in this study:
  • 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)
  • 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)
  • 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
  • History of an eating disorder by self-report or medical history
  • Food allergies/intolerances or dietary patterns that would prohibit consumption of metabolic diet
  • Inability to provide informed consent
  • Pregnancy or lactation
  • Unstable weight with more than 5% body weight change in last previous 3 months
  • 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
  • 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.

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

National Institutes of Health Clinical Center

Bethesda, Maryland, 20892, United States

RECRUITING

Related Publications (2)

  • Han K, Nguyen A, Traba J, Yao X, Kaler M, Huffstutler RD, Levine SJ, Sack MN. A Pilot Study To Investigate the Immune-Modulatory Effects of Fasting in Steroid-Naive Mild Asthmatics. J Immunol. 2018 Sep 1;201(5):1382-1388. doi: 10.4049/jimmunol.1800585. Epub 2018 Jul 18.

    PMID: 30021766BACKGROUND
  • Puchalska P, Crawford PA. Metabolic and Signaling Roles of Ketone Bodies in Health and Disease. Annu Rev Nutr. 2021 Oct 11;41:49-77. doi: 10.1146/annurev-nutr-111120-111518.

    PMID: 34633859BACKGROUND

Related Links

MeSH Terms

Conditions

ObesityBody WeightIntermittent FastingInflammation

Condition Hierarchy (Ancestors)

OverweightOvernutritionNutrition DisordersNutritional and Metabolic DiseasesSigns and SymptomsPathological Conditions, Signs and SymptomsFastingFeeding BehaviorBehaviorPathologic Processes

Study Officials

  • Stephanie T Chung, M.D.

    National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

    PRINCIPAL INVESTIGATOR

Central Study Contacts

Stephanie T Chung, M.D.

CONTACT

Study Design

Study Type
interventional
Phase
not applicable
Allocation
NA
Masking
NONE
Purpose
BASIC SCIENCE
Intervention Model
SINGLE GROUP
Sponsor Type
NIH
Responsible Party
SPONSOR

Study Record Dates

First Submitted

December 11, 2023

First Posted

December 13, 2023

Study Start

September 4, 2024

Primary Completion (Estimated)

February 5, 2027

Study Completion (Estimated)

February 5, 2027

Last Updated

August 22, 2025

Record last verified: 2025-08-20

Data Sharing

IPD Sharing
Will share

The investigators will provide raw data (without identifying information) to journals or other researchers upon request.

Shared Documents
STUDY PROTOCOL, ICF
Time Frame
The data will be provided upon request within 1 year after publication and will be available to indefinitely
Access Criteria
The PI will accept requests from other researchers who are examining pertinent outcomes

Locations