Impact of a Short-Term Mediterranean-Style Diet on Health Indices (MEDWELL)

July 15, 2026 updated by: DR ADELE COSTABILE, University of Roehampton

Exploring the Effects of a Short-term Mediterranean-style Dietary Intervention on Indices of Mood and Wellbeing in UK Adults

Emerging evidence suggests protective properties of a Mediterranean diet (MD) in relation to prevention and management of mood disorders. However, there is paucity of dietary interventions investigating adherence to MD and effects on mood and wellbeing in individuals without a clinical diagnosis. The present study aimed to investigate the effects of adherence to a short-term MD on mood and wellbeing in healthy adults

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

This is a 1-week, cross-over, randomised, controlled study investigating the effects of Mediterranean style diet on perceived mood and overall wellbeing in healthy adults. The intervention consists following daily for 1 week a Mediterranean style eating pattern. Participants are following their habitual diet during the control week. This is an investigator-initiated, randomised, cross-over, controlled study.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
22

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • 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 Kingdom
    • UK
      • London, UK, United Kingdom, SW15 4JD
        • University of Roehampton, School of Life and Health Sciences

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Habitual diet of low Mediterranean Diet (MD)adherence i.e. individuals with MD scoring ≤7 (low adherence) were included.
  • Living in UK

Exclusion Criteria:

  • pregnant or breastfeeding following a weight loss diet
  • diagnosed medical condition (diabetes, cardiovascular disease, cancer, food allergies)
  • have any further health conditions which may cause you to react adversely whilst changing your diet.
  • diagnosed with a neurological impairment or psychiatric disorder
  • Current smoker (last 12 months)
  • history of substance abuse
  • taking dietary supplements
  • already following a Mediterranean style diet

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: Treatment
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Active Comparator: A Mediterranean style diet
At baseline, participants attended an Educational Group Session (EGS) introducing the principles of the Mediterranean Diet (MD), including recommended foods, foods to limit, cooking methods, and shopping tips. Participants then followed a Mediterranean-style diet for 7 days, replacing typical Western foods with MD alternatives without restricting energy intake. Practical examples and take-home materials with simple food swaps were provided to support adherence.
Other: A mediterranean style diet
At baseline, an Educational Group Session (EGS) introduced participants to the Mediterranean Diet (MD) principles to support adherence. The interactive EGS covered MD typical foods to consume and avoid, cooking methods, and practical shopping guidance. Following the EGS, participants adopted a Mediterranean-style diet for a period of 7 days. Participants were encouraged to follow the MD guidelines (replacing typical western foods with MD foods) without restricting energy intake; examples were provided during the EGS and with take-home resource materials which detailed 'simple swaps' or alternative MD food items to replace western food items.
Other Names:
  • MD
Placebo Comparator: Habitual diet
Participants were instructed to follow their habitual diet (control) and eating practices for 7 days. without restricting energy intake.
Other: Habitual Diet
participants were instructed to follow their habitual diet (control) and eating practices for 7 days. without restricting energy intake.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Mood
Time Frame: Baseline and 7 days (final day of each condition) espressed in questionnaire scores
Change in mood measured using the Bond-Lader Visual Analogue Scale (VAS). The scale ranges from 0 to 100, with higher scores indicating a more positive mood state (better outcome).
Baseline and 7 days (final day of each condition) espressed in questionnaire scores

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Wellbeing
Time Frame: Baseline and 7 days (final day of each condition) espressed in questionnaire scores
Change in wellbeing measured using the Warwick-Edinburgh Mental Wellbeing Scale (WEMWBS). The WEMWBS total score ranges from 14 to 70, with higher scores indicating greater mental wellbeing (better outcome).
Baseline and 7 days (final day of each condition) espressed in questionnaire scores

Other Outcome Measures

Other Outcome Measures

For clinical trials, a planned measurement described in the protocol that is used to determine the effect of an intervention/treatment on participants. For observational studies, a measurement or observation that is used to describe patterns of diseases or traits, or associations with exposures, risk factors, or treatment. Types of outcome measures include primary outcome measure and secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Body weight
Time Frame: Baseline and 7 days (final day of each condition) expressed in Kg

Change in body weight, measured in kilograms (kg)

Change in waist circumference, measured in centimetres (cm). Lower waist circumference indicates a better outcome where reduction in central adiposity is a study objective.
Baseline and 7 days (final day of each condition) expressed in Kg
Physical activity
Time Frame: Baseline and 7 days (final day of each condition) espressed in questionnaire scores
Change in physical activity measured using the International Physical Activity Questionnaire (IPAQ), expressed as total metabolic equivalent (MET)-minutes per week. Higher scores indicate greater physical activity levels (better outcome). The IPAQ does not have a fixed minimum or maximum score.
Baseline and 7 days (final day of each condition) espressed in questionnaire scores
Dietary intake
Time Frame: During the 7 days intervention/condition using DietPlan software
Change in dietary intake assessed using 7-day weighted food records collected during each 7-day intervention period. Dietary intake was quantified as daily energy and nutrient intake. There is no fixed minimum or maximum score; values are reported in their respective units (e.g., kcal/day, g/day). The direction of a better outcome depends on the specific dietary component being evaluated.
During the 7 days intervention/condition using DietPlan software

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University of Roehampton

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Fotini Tsofliou, University of Roehampton

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)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
March 1, 2019

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
May 12, 2019

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
August 20, 2019

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
June 19, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 15, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
July 16, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
July 16, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 15, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
July 1, 2026

More Information

Terms related to this study

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • MED-MOOD-UK-2026-001

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

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.

Cookie Settings

We use cookies to ensure that we give you the best experience on our website. For more details carefully read our Privacy and Cookies Policy. ...>>>You can change your preferences or withdraw your consent at any time by deleting the cookies from your website or computer as described in the policy. Please accept it and choose your preferences by ticking the corresponding boxes in the "Manage Settings" section below. Please carefully read our Terms of Service before you proceed with using any part of this website.
«Manage Settings