Feasibility and Preliminary Effects of Fasting-Mimicking Diet in Asian Americans With Prediabetes

September 24, 2025 updated by: Hannah Lui Park, University of California, Irvine

Pilot Study on Fasting-Mimicking Diet in Asian Americans With Prediabetes

This is a pilot study to determine the feasibility of studying the Fasting-Mimicking Diet (FMD), a dietary approach that involves the consumption of a specifically formulated, calorie-restricted nutrition regimen with a customized macronutrient composition, ratio, and quantity over a 5- day period, on a larger scale in Asian Americans with prediabetes and to examine the preliminary effects of the diet in study participants.

The main questions the study aims to answer are:

  1. What are the recruitment, adherence, and attrition rates of eligible participants into the study?
  2. Does one FMD cycle result in changes in fasting blood glucose levels and physical measurements in study participants?

Participants will be asked to undergo one cycle of FMD (for 5 days), fill out surveys, and come in for a pre-FMD and post-FMD study visit, during which physical measurements and fasting blood glucose and ketone levels will be measured.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

30

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • California
      • Irvine, California, United States, 92617
        • UC Irvine

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion criteria:

  • Identify as Asian American
  • Diagnosed with prediabetes according to at least one of the following:
  • HbA1C 5.7%-6.4%
  • Fasting blood glucose 100 to 125 mg/dL (5.6 to 6.9 mmol/L )
  • Oral glucose tolerance test (OGTT) 140-199 mg/dL at two hours

Exclusion criteria:

  • Individuals with a personal history of diabetes mellitus (ICD-10 codes E08-E13), cardiovascular disease, mental illness, drug dependency, pregnancy, and special dietary restrictions
  • Individuals taking insulin or insulin-like drugs and individuals taking hypoglycemic agents other than metformin
  • Individuals who are pregnant or breastfeeding
  • Individuals with anaphylaxis food allergies
  • Individuals who are allergic to tree nuts (macadamia, cashew, almond, pecan), soy, oats, sesame, or celery/celeriac
  • Individuals who have completed the FMD in the past year

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Fasting Mimicking Diet (FMD)
The fasting-mimicking diet (FMD) group will be instructed on the benefits and use of the FMD kit. Participants will be given one 5-day FMD kit at their baseline visit. They will be instructed to follow the kit, and only eat its items, for five consecutive days and to report back for a follow-up visit and measurements at the end of their 5 days before returning to their normal diet.
Behavioral: Fasting Mimicking Diet
Participants will be instructed to follow their usual diet except for 5 days when they eat the foods in the FMD kit. The FMD consists of a blend of 100% plant based nutrients generally regarded as safe. One FMD kit provides for the replacement of the normal diet with plant products for five consecutive days. The formulation of these products was based on studies carried out at the Longevity Institute of the University of Southern California, led by Dr. Valter Longo and his collaborators over several decades of research.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Recruitment rate
Time Frame: up to 6 months
Recruitment rate will be determined based on the number of individuals who consented to be in the pilot Fasting Mimicking Diet trial per month.
up to 6 months
Adherence rate
Time Frame: up to 6 months
Study adherence will be assessed based on the participant's changes in fasting blood glucose and blood ketone levels measured pre- vs. post- Fasting Mimicking Diet (FMD); a post-FMD survey asking about adherence to the FMD; and attending the follow-up study appointment. The survey will also ask for participants' feedback on their experiences of the trial, including adverse events, and, if applicable, reasons for non-adherence, to enable further study optimization.
up to 6 months
Attrition rate
Time Frame: up to 6 months
Attrition rate will be determined based on the number of individuals who stopped consuming the Fasting Mimicking Diet or never started.
up to 6 months
Willingness to participate in a future full Fasting Mimicking Diet (FMD) clinical trial
Time Frame: up to 6 months
Willingness to participate in a future full FMD clinical trial (which would have 4 FMD cycles + additional study appointments at 4 months after the last FMD cycle) will also be assessed via survey at the conclusion of their participation in this pilot.
up to 6 months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in fasting blood glucose levels
Time Frame: Pre v. post 5-day FMD cycle
Fasting blood glucose levels will be compared pre v. post 5 days of Fasting Mimicking Diet (FMD) (using a lancet and glucose meter)
Pre v. post 5-day FMD cycle
Change in blood pressure
Time Frame: Pre v. post 5-day FMD cycle
Systolic and diastolic blood pressure will be compared pre v. post 5 days of Fasting Mimicking Diet (FMD)
Pre v. post 5-day FMD cycle
Change in body mass index
Time Frame: Pre v. post 5-day FMD cycle
Body mass index will be compared pre v. post 5 days of Fasting Mimicking Diet (FMD)
Pre v. post 5-day FMD cycle
Change in percent body/visceral fat
Time Frame: Pre v. post 5-day FMD cycle
Percent body fat and percent visceral fat will be compared pre v. post 5 days of Fasting Mimicking Diet (FMD)
Pre v. post 5-day FMD cycle
Change in waist circumference
Time Frame: Pre v. post 5-day FMD cycle
Waist circumference will be compared pre v. post 5 days of Fasting Mimicking Diet (FMD)
Pre v. post 5-day FMD cycle
Change in ketone levels
Time Frame: Pre v. post 5-day FMD cycle
β-Hydroxybutyrate level will be compared pre v. post 5 days of Fasting Mimicking Diet (FMD) using a lancet and blood ketone meter
Pre v. post 5-day FMD cycle

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of California, Irvine

Collaborators

University of Southern California

Investigators

  • Principal Investigator: Hannah Lui Park, PhD, University of California, Irvine

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

August 12, 2024

Primary Completion (Actual)

May 9, 2025

Study Completion (Actual)

May 9, 2025

Study Registration Dates

First Submitted

July 12, 2024

First Submitted That Met QC Criteria

July 18, 2024

First Posted (Actual)

July 24, 2024

Study Record Updates

Last Update Posted (Estimated)

September 30, 2025

Last Update Submitted That Met QC Criteria

September 24, 2025

Last Verified

September 1, 2025

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 4223

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

De-identified individual participant data will be available from the corresponding author on reasonable request.

IPD Sharing Time Frame

Starting 6 months after publication

IPD Sharing Access Criteria

Upon review by the study investigators

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • ICF
  • CSR

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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