High‑phenolic versus low‑phenolic extra virgin olive oil for metabolic health in adults with central obesity

Is this trial a fit for you?

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

The study is a double‑blind, randomized, controlled trial enrolling 70–80 adults with overweight or obesity and at least one metabolic abnormality. Participants are randomized 1:1 to consume either high‑phenolic olive oil (>1000 mg/kg total polyphenols) or low‑phenolic olive oil (≤100 mg/kg) daily for eight weeks, with oil amounts tailored to individual fat‑energy targets alongside standardized mild weight‑loss dietary guidance. Key exclusions include untreated or insulin‑treated diabetes, major acute or chronic diseases, use of antioxidant‑rich supplements, pregnancy or lactation, and substance abuse. Outcomes include changes in blood lipids, glucose/insulin markers, and biomarkers of oxidative stress and inflammation collected at baseline and follow‑up.

Why it matters

Who can join: the full rules

Inclusion Criteria:

* Adult men and women 18-80 years of age,
* Overweight/obesity (body mass index \> 25 or waist circumference \>94 cm for males and \>80 cm for females), and
* The presence of at least one of the following metabolic abnormality: (1) triglyceride level ≥150 mg/dL or HDL cholesterol ≤40 mg/dL in men and ≤50 mg/dL in women; (2) increased blood pressure ≥ 130/85 mm Hg; (3) elevated fasting blood sugar ≥100 mg/dL; (4) standardized drug treatment regimen, and
* Provided signed informed consent for participation.

Exclusion Criteria:

* Concomitant acute or chronic disease (e.g., infection, cancer, chronic heart failure, kidney disease, autoimmune diseases like rheumatoid arthritis, inflammatory bowel diseases, Hashimoto),
* Untreated diabetes,
* Women at pregnancy or lactation,
* Individuals with psychiatric or mental disorder,
* Any use of antioxidant-phytochemical rich supplement, anti-, pre- or probiotics pre-intervention,
* Drug and/or alcohol abuse,
* Those who did not consent or were unable to provide consent.

Where it's running

• Antikalamos Facilities of University of Peloponnese
  Kalamata, Greece Recruiting

Study contacts

• Principal investigator: Aristea Gioxari — Department of Nutritional Science and Dietetics, School of Health Sciences, University of Peloponnese
• Study coordinator: Aristea Gioxari, Assistant Professor
• Email: a.gioxari@go.uop.gr
• Phone: +302721045326

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How to take part

1. Review the eligibility criteria above with your treating physician.
2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.