Comparative Effects of Carnivore and Mediterranean-style Diets on LDL Aggregation and Cardiometabolic Health (MEDIVORE)

Comparative Effects of Carnivore and Mediterranean-style Diets on LDL Aggregation Susceptibility and Cardiometabolic Health

The goal of this clinical trial is to learn whether following a Mediterranean-style diet or a Carnivore-style diet can improve heart and metabolic health in men and women aged 30-60 years with high LDL cholesterol.

The main questions it aims to answer are:

1. Does following a Mediterranean or Carnivore diet change how easily LDL cholesterol particles clump together (LDL aggregation susceptibility)?
2. Do these two diets have different effects on other measures of heart and metabolic health, such as blood fats, blood vessel function, and overall wellbeing?

Researchers will compare people who follow the Mediterranean-style diet with those who follow the Carnivore-style diet to see which diet produces more beneficial changes in cholesterol and heart health markers.

Participants will:

• Attend three visits at Liverpool John Moores University for screening and data collection.
• Be randomly assigned to follow either the Mediterranean or Carnivore diet for 3 weeks, matched for calories and protein.
• Provide fasting blood, urine, and stool samples before and after the diet period.
• Complete non-invasive cardiovascular tests to measure blood vessel and heart function.
• Take part in a short interview and complete questionnaires about their experience of following the diet.

Study Overview

• Status: Not yet recruiting
• Conditions: Metabolic Syndrome; Dyslipidaemia; Atherosclerosis Cardiovascular Disease
• Intervention / Treatment: Dietary supplement: Mediterranean Diet; Dietary supplement: Carnivore Diet

• Study Type: Interventional
• Enrollment (Estimated): 30
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Megan Wilson, BSc Nutrition; Phone Number: +447362317430; Email: M.L.Wilson@ljmu.ac.uk
• Study Contact Backup: Name: Dr Richie Kirwan; Email: R.P.Kirwan@ljmu.ac.uk

Study Locations

• United Kingdom
  • Liverpool, United Kingdom, L3 3AF
    • Tom Reilly Building, Liverpool John Moores University
    • Contact: Dr Richie Kirwan; Email: R.P.Kirwan@ljmu.ac.uk
    • Contact: Megan Megan Wilson; Phone Number: 447362317430; Email: M.L.Wilson@ljmu.ac.uk

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Male or female
• 30-60 years of age
• Elevated LDL cholesterol (LDL >3mmol/L and/or non-HDL cholesterol > 4mmol/L)
• Not following any specific diet for health reasons.
• Not currently taking lipid-lowering medications or supplements that may interfere with LDL levels.

Exclusion Criteria:

• Pregnancy or breastfeeding.
• Known food allergies or intolerances.
• Previous history of disordered eating.
• Currently taking cholesterol-lowering medication or supplements.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Mediterranean-style diet; Participants will be provided with an isocaloric diet rich in fruits, vegetables, whole grains, legumes, nuts, olive oil, and fish, consistent with and optimised to reflect a traditional Mediterranean dietary pattern. The diet will include moderate amounts of poultry and dairy products and limited amounts of red and processed meat, refined carbohydrates, and added sugars.	Dietary supplement: Mediterranean Diet; The intervention diet will consist of isocaloric consumption of foods typical of a traditional Mediterranean dietary pattern, including fruits, vegetables, whole grains, legumes, nuts, olive oil, and fish, for a period of 3 weeks. The diet will include moderate amounts of poultry and dairy products and limited amounts of red and processed meat, refined carbohydrates, and added sugars.
Experimental: Carnivore-style diet; Participants will be provided with an isocaloric diet consisting primarily of animal-based products, including red meat, poultry, and limited amounts of dairy products. The diet will exclude plant-based foods, such as fruits, vegetables, grains, legumes, nuts, and seeds to reflect a traditional Carnivore-style dietary pattern.	Dietary supplement: Carnivore Diet; The intervention diet will consist of isocaloric consumption of exclusively of animal-based products, including red meat, poultry, and limited amounts of dairy products for 3 weeks. The diet will exclude plant-based foods, such as fruits, vegetables, grains, legumes, nuts, and seeds to reflect a traditional Carnivore-style dietary pattern.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
LDL aggregation susceptibility	To measure changes in how easily LDL cholesterol particles 'clump' together in the blood vessels from baseline to post-intervention, assessed via plasma lipid and lipoprotein analysis.	Baseline and 3 weeks.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Plasma lipid and lipoprotein profile	Changes in plasma levels of total cholesterol, LDL cholesterol, HDL cholesterol, triglycerides will be determined via enzymatic analysis and measured in mmol/L.	Baseline and 3 weeks.
Lipoprotein particle size	Changes in lipoprotein particle size (diameter) will be measured via Nuclear Magnetic Resonance spectroscopy (NMR) and expressed in nanometers.	Baseline and 3 weeks.

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Blood pressure	Change in resting systolic and diastolic blood pressure. Blood pressure reflects cardiovascular function and may be influenced by dietary fat type and nutrient composition.	Baseline and 3 weeks.
Flow-mediated dilation (FMD)	Change in blood vessel function will be assessed using a non-invasive ultrasound test to measure how well the arteries widen (dilate) in response to increased blood flow.	Baseline and 3 weeks.
Plasma glucose	Changes in fasting blood glucose will be assessed via biochemical plasma analysis of a venous blood sample and recorded in mmol/L.	Baseline and 3 weeks.
Dietary adherence	Participants' self-reported adherence to the assigned diet will be collected through completion of a 3-day online food log/diary via a mobile phone application.	Baseline and 3 days during the intervention.
Pulse wave velocity (PWV)	Non-invasive ultrasound measurement of how quickly blood pressure waves move through the carotid artery.	Baseline and 3 weeks.
Carotid intima media thickness (CIMT)	CIMT is a non-invasive ultrasound method used to measure the thickness of an artery wall which can give information about blood vessel health.	Baseline and 3 weeks.
Height	Height will be measured in metres using a stadiometer.	Baseline and 3 weeks.
Body weight	Changes in body weight will be measured in kilograms using a SECA bioelectrical impedance analyser.	Baseline and 3 weeks.
Body mass index (BMI)	BMI will be calculated calculated by dividing an adult's weight in kilograms by their height in meters squared.	Baseline and 3 weeks.
Body fat percentage	Using a SECA bioelectrical impedance analyser, body fat percentage will be estimated by sending a weak, painless electrical current through the body, measuring the resistance (impedance) encountered.	Baseline and 3 weeks.
Waist to hip ratio	Waist to hip ratio will be measured using a measuring tape to measure the narrowest point of the waist and the widest point of the hips. The ratio will be calculated by dividing waist circumference by hip circumference (WHR = Waist ÷ Hip) using the same unit of measurement (cm or inches).	Baseline and 3 weeks.
Plasma insulin	Changes in fasting blood insulin levels will be assessed via biochemical plasma analysis of a venous blood sample and recorded in mcU/mL.	Baseline and 3 weeks.
Homeostatic Model Assessment of Insulin Resistance (HOMA-IR)	HOMA-IR measures insulin resistance using fasting blood glucose and insulin, with a score of > 2.0 or 2.5 typically indicating resistance.	Baseline and 3 weeks.
Qualitative interview	Participants will complete a semi-structured exit interview (~30-45 minutes) to explore their experiences of their assigned dietary intervention. Interviews will assess acceptability, feasibility, and perceived impacts of the diet and intervention procedures. Question subsections include overall experience, practical challenges, social and lifestyle factors, and intentions to continue the diet. Interviews will be conducted in person or online via Microsoft Teams, audio-recorded with consent, transcribed verbatim, and anonymised prior to thematic analysis.	Post-intervention

Collaborators and Investigators

• Sponsor: Liverpool John Moores University
• Collaborators: University of Helsinki; Wihuri Research Institute

Study record dates

Study Major Dates

• Study Start (Estimated): June 1, 2026
• Primary Completion (Estimated): June 1, 2027
• Study Completion (Estimated): June 1, 2027

Study Registration Dates

• First Submitted: February 10, 2026
• First Submitted That Met QC Criteria: March 5, 2026
• First Posted (Actual): March 10, 2026

Study Record Updates

• Last Update Posted (Actual): March 13, 2026
• Last Update Submitted That Met QC Criteria: March 11, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: Atherosclerosis; Lipid metabolism; ASCVD; Lipoproteins; Diet, carbohydrate-restricted; Ketogenic diet; LDL aggregation; Low-density lipoproteins
• Additional Relevant MeSH Terms: Vascular Diseases; Cardiovascular Diseases; Metabolic Diseases; Glucose Metabolism Disorders; Insulin Resistance; Hyperinsulinism; Lipid Metabolism Disorders; Arteriosclerosis; Arterial Occlusive Diseases; Nutritional and Metabolic Diseases; Metabolic Syndrome; Dyslipidemias; Atherosclerosis; Therapeutics; Diet, Food, and Nutrition; Physiological Phenomena; Nutritional Physiological Phenomena; Diet, Plant-Based; Diet Therapy; Nutrition Therapy; Diet; Diet, Mediterranean
• Other Study ID Numbers: SLNMWILSRCT

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED
• IPD Plan Description: The research team intends to consider sharing de-identified individual participant data after publication of the primary results, subject to participant consent, ethical approval, and institutional data governance review. A formal IPD sharing plan will be developed in collaboration with Liverpool John Moores University once data has been fully analysed.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No