Recruiting

Fasting

Sponsor:

UCLA

Code:

NCT05104502

Conditions

Fasting

Eligibility Criteria

Sex: All

Age: 20 - 40

Healthy Volunteers: Accepted

Interventions

Dietary Fasting

Study Details

Brief summary:

This is a clinical trial assessing the effects of fasting on the immune system in healthy adults. Immune profiling, gene expression profiling, and flow cytometry on peripheral blood mononuclear cells (PBMCs) will be performed and we hypothesize that a period of fasting will alter the immune system in healthy adults.

Conditions

Fasting

Study ID

NCT05104502

Start date

Mar 25, 2022

Status verified date

Jul, 2026

Completion date

Sep, 2026

Anticipated

Primary completion date

Sep, 2026

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 20 - 40

Healthy Volunteers: Accepted

Inclusion Criteria:

  • Age: 20-40 years, to constitute a young study population
  • Gender: male subjects, to control for gender differences
  • BMI: 19-27 kg/m2 to constitute a normal/healthy weight population
  • Weight: 120 lbs or more
  • Fasting glucose: 70-100 mg/dL, to ensure that fasting can be tolerated without inducing dangerously low levels of blood glucose
  • Subjects must be willing to undergo a period of 36 hours of water-only fasting
  • Subjects must be willing to collect samples of each bowel movement produced throughout the entire study period for microbiome analysis
  • Subjects must be willing to collect blood pricks for blood glucose levels using a Contour Next One Blood Glucose Testing Kit during the fasting stage of the study protocol.

Exclusion Criteria:

  • Current smoking
  • Anemia
  • Pregnancy or current breastfeeding
  • Chronic diseases including diabetes mellitus, thyroid disease, metabolic syndrome, cancer, or previous cardiovascular events
  • Gastrointestinal diseases including irritable bowel syndrome, Crohn's disease, ulcerative colitis, celiac disease
  • Consumption of >1 alcoholic drink/day
  • Extreme dietary or exercise patterns
  • Recent weight fluctuations (greater than 10% in the last six months)
  • Regular use of over-the-counter allergy or pain medications (>1/week)
  • Taking prescription lipid medications (e.g. statins) or other supplements known to alter lipoprotein metabolism such as isoflavones
  • Use of hormonal birth control including oral contraception pills, hormonal IUDs or rings, or hormonal birth control patches

Study Design

Enrollment

4 participants

Anticipated

Intervention Model

Single group

Primary purpose

Basic Science

Interventions and Outcome Measures

Arms

experimental: Fasting

Dietary fasting.

Interventions

Dietary Fasting

The study will consist of two days of eating a "controlled habitual diet" and one 36-hour period of water-only fasting with glucose monitoring as a measure of compliance. Water intake will be limited to 2 liters/day to prevent electrolyte abnormalities. Subjects will undergo 4 separate blood-draws consisting of an overnight fasted sample (Baseline), a 2-hour postprandial sample (Fed), a 36-hour fasted sample (Fasted), and final 2-hour postprandial sample after the fasting period (Refed).

Primary outcome measure

  • Changes in peripheral blood mononuclear cells [ Time Frame: 7 months ]

Central Contacts and Locations

Central contacts

Antonio Ji

916-551-2630ajixu@ucdavis.edu

Locations

UC Davis

Recruiting

Sacramento, California, United States, 95816

More Information

Sponsor

University of California, Davis

Last update posted

Jul 6, 2026

Last verified

Jul, 2026

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by University of California, Davis on 2026-07-06.