Pilot Study of Isocaloric Time Restricted Eating on Ketone Metabolism and Immunoregulation

Obesity Clinical Trial

Official title: Pilot Study of Isocaloric Time Restricted Eating on Ketone Metabolism and Immunoregulation

Status Not yet recruiting

Clinical Trial 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.

Clinical Trial Description

Study Description:

Intermittent fasting confers anti-inflammatory effects, although underlying metabolic mechanisms are poorly defined. This pilot study will explore ketone bodies as a mediator of inflammation in response to time restricted eating (TRE-6-hr feeding/18-hr fast) without caloric restriction compared to a more conventional dietary regimen (12-hr feeding/12-hr fast) in women classified as obese and lean.

Objectives:

Primary Aim 1: Quantify ketone body (beta-OHB) whole-body turnover after short-term early 6-hr TRE compared to a conventional 12-hr dietary regimen in women.

Primary Aim 2: Quantify CD4+ T cell responses after short-term early 6-hr TRE compared to a conventional 12-hr dietary regimen in women.

Secondary Aim 1: Determine metabolic response to short-term early 6-hr TRE in lean women vs women with obesity.

Secondary Aim 2: Determine immunomodulatory effects of short-term early 6-hr TRE in lean women vs women with obesity.

Exploratory Aim 1: Evaluate ketone body, hormonal, and cardiometabolic responses after short-term early 6-hr TRE compared to a conventional 12-hr dietary regimen in women classified as lean and with obesity.

Exploratory Aim 2: Evaluate effects of short-term early 6-hr TRE on perceived appetite, stress, and gastrointestinal symptoms.

Endpoints:

Primary:

1. Change from admission day 0 in ketone body (beta-OHB) rate of appearance (Ra) after three days of 6-hr TRE

2. Change from admission in CD4+ T cell responsiveness (Th17 polarization) after three days of 6-hr TRE

Secondary:

1. Change from admission day 0 in post-absorptive glucose Ra quantified using [6,6-2H2]glucose (intravenous) after three days 6- hr TRE

2. Change from admission day 0 in ketone body Ra in lean vs. obese women after three days 6-hr TRE

3. CD4+ T cell responsiveness (Th17 polarization) in lean vs. obese women after three days 6-hr TRE

4. Evaluation of ketone biology in isolated CD4+ T cells, using biochemical analysis and analysis of metabolic reprograming at the gene regulatory level

Exploratory:

1. Circulating ketone body concentrations at admission day 0 and after 3 days of TRE

2. Hormonal mediators of metabolic status (morning cortisol, fasting insulin and glucagon/incretins, thyroid hormones, sex hormone binding globulin, anti-mullerian hormone)

3. Cardiometabolic biomarkers (glycemic, lipid, and inflammatory; trimethylamine N-oxide[TMAO])

4. Perceived appetite, stress, and gastrointestinal symptom scores ;

Related Conditions & MeSH terms

• Body Weight
• Obesity

• NCT number: NCT06169137
• Study type: Interventional
• Source: National Institutes of Health Clinical Center (CC)
• Contact: Lilian S Mabundo
• Phone: (240) 383-9379
• Email: lilian.mabundo@nih.gov
• Status: Not yet recruiting
• Phase: N/A
• Start date: June 26, 2024
• Completion date: February 5, 2027