A diet program combining intermittent energy restriction and the Mediterranean diet

Effects of Intermittent Energy Restriction on Intra-Abdominal Fat and the Gut Microbiome: A Randomized Trial

Not applicable Interventional University of Hawaii · NCT05132686

This study is testing whether a diet that combines intermittent energy restriction with the Mediterranean diet can help middle-aged adults with high belly fat lose weight and improve their health compared to a daily diet plan.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment260 (estimated)
Ages35 Years to 69 Years
SexAll
SponsorUniversity of Hawaii Academic / other
Drugs / interventionschemotherapy, radiation
Locations1 site (Honolulu, Hawaii)
Trial IDNCT05132686 on ClinicalTrials.gov

What this trial studies

This study investigates the effectiveness of a 24-week randomized trial comparing intermittent energy restriction (IER) combined with the Mediterranean diet (MED) to a daily energy restriction (DER) approach among 260 middle-aged adults with high visceral fat. Participants will be randomly assigned to either the IER+MED group, which follows a specific eating pattern of energy restriction for two days a week, or the MED/DER group, which maintains a daily energy restriction. The trial aims to assess reductions in abdominal visceral fat, liver fat, and overall adiposity, as well as the impact on cancer-related biomarkers and gut microbiome. The study is designed to include a diverse population, focusing on East-Asian, Native Hawaiian, and white ethnicities.

Who should consider this trial

Good fit: Ideal candidates are middle-aged adults aged 35-69 with a BMI between 25-40 kg/m2 and high visceral fat levels.

Not a fit: Patients with serious health issues, pregnancy, or contraindications to MR imaging will not benefit from this study.

Why it matters

Potential benefit: If successful, this study could provide a more effective dietary approach for reducing visceral fat and improving metabolic health in at-risk populations.

How similar studies have performed: Previous studies have shown promising results for intermittent energy restriction and Mediterranean diets, but this specific combination is being rigorously tested for the first time.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Age 35-69 years old
* BMI between 25-40 kg/m2
* Currently non-smoking
* No serious health issues
* Fully vaccinated for COVID-19
* Normal blood chemistry profile
* East Asian (Chinese, Japanese, Korean), Filipino, Native Hawaiian/other Pacific Islander or white/European ancestry
* Non-drinkers / low habitual drinkers, i.e., men ≤15 drinks per week, women ≤10 drinks per week
* Volunteers living on the island of Oahu
* For peri-menopausal women, the investigators will require that they had their last period at least 1 year before baseline)
* DXA VAT ≥90 cm2 for men and ≥80 cm2 for women
* Able to read, speak, and write in English

Exclusion Criteria:

* Pregnancy
* Contraindication to MR imaging (e.g. pacemaker, claustrophobia, metal implants)
* Previous surgery to remove any part of the small intestine, colon or rectum (e.g.

ileostomy or colectomy) or an amputation of a leg or arm.

* For women, taking any anti-estrogen medications (e.g tamoxifen, Nolvadex, Istubal, Valodex)
* For men, taking any anti-androgen medications (e.g., Eulexin (flutamide); Anandron or Nilandron (nilutamide); Casodex (bicalutamide); Proscar or Propecia (finasteride); Avodart (dutasteride); or bexlosteride, izonsteride, turosteride, episteride).
* Diagnosis of Type 1 diabetes or Type 2 diabetes and taking insulin for treatment
* Diagnosis of thyroid conditions under treatment with hormones or medications.
* Serious health issues such as dialysis, organ transplant, celiac disease, Crohn's disease, chronic liver disease, active case of hepatitis B or C, chronic kidney disease, or any condition that, in the opinion of the investigator, is a contraindication to participation.
* Previous problem with fasting blood collection
* Cannot exercise (walk) for up to 1hr/day

Deferral Criteria :

Volunteers with the following conditions will be called back after the specified duration:

* Treatments in past 6 months: chemotherapy or radiation of abdomen/pelvis; corticosteroid hormones; prescription weight loss drugs; estrogen/androgen receptor blockers
* Substantial weight change (\>20lbs) in past 6 months
* Antibiotic use in past 3 months
* Colonoscopy, sigmoidoscopy, colon irrigation/bowel cleaning in the past 3 months
* MRI/CAT scan with contrast in the past 2 weeks

Where this trial is running

Honolulu, Hawaii

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Intra-Abdominal FatVisceral Adipose Tissue, Visceral FatIntermittent energy restrictionRandomized Controlled TrialAdiposity
Last reviewed 2026-06-09 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.