AzTrials
AzTrials

Overweight (BMI > 25)NCT07314177

Effects of Three Dietary Strategies on Body Composition and Metabolic Health in Adults With Overweight or Obesity

A study testing Mediterranean Diet, Mediterranean Low-Carbohydrate Diet and High-Protein Diet in people with Overweight (BMI > 25) and Obesity &Amp; Overweight, run by Consorcio Centro de Investigación Biomédica en Red (CIBER) at 1 site in Spain.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
Search all trials

Trial summary

This study aims to compare the effects of three dietary interventions-a traditional Mediterranean diet, a Mediterranean low-carbohydrate diet, and a high-protein diet-on body composition, metabolic health markers, and metabolic syndrome remission in adults with overweight or obesity. Read more about this study

Who is it for?
Ages 20 to 70 years
What is being tested?
Mediterranean Diet, Mediterranean Low-Carbohydrate Diet and High-Protein Diet
Could I receive a placebo?
No, everyone receives an active treatment
How many people
45 participants
Where
1 siteSpain
Study dates
8 Sep 2024to 25 Jun 2025
Phase
Interventional
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 20 to 70 years
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • Adults aged 20-70 years
  • Body mass index (BMI) ≥ 25 kg/m² (overweight or obesity)
  • Stable body weight (± 2 kg) in the last 3 months prior to screening
  • Willingness to follow one of the prescribed dietary interventions for 12 weeks
  • Ability to attend scheduled follow-up visits and complete study assessments
  • Provided written informed consent prior to study participation

Who cannot join

  • Diagnosis of type 1 diabetes, cardiovascular disease, cancer, chronic kidney disease, liver disease, or other serious chronic conditions that could interfere with the intervention
  • Pregnancy or breastfeeding
  • Current participation in another clinical trial
  • History of bariatric surgery or weight-loss program within the past 6 months
  • Use of medications known to affect body weight, metabolism, or appetite (e.g., glucocorticoids, weight-loss drugs, antipsychotics)
  • Any food allergy or intolerance that would preclude adherence to the assigned diet
  • Alcohol or substance abuse
  • Any condition or circumstance that, in the opinion of the investigators, would make the participant unsuitable for the study

Trial locations and contacts

1 site in 1 country.

Spain1 site
  • Edificio SAI

    Zaragoza

Other trials in Spain

About this study

Official title: Comparative Effects of Three Dietary Strategies on Body Composition, Metabolic Markers, and Metabolic Syndrome in Adults With Overweight/Obesity: A Randomized Pilot Trial

This study aims to compare the effects of three dietary interventions-a traditional Mediterranean diet, a Mediterranean low-carbohydrate diet, and a high-protein diet-on body composition, metabolic health markers, and metabolic syndrome remission in adults with overweight or obesity. A total of 45 participants will be randomly assigned to one of the three diets for 12 weeks, with regular follow-up by dietitians. Measurements will include weight, body fat, muscle mass, waist and hip circumference, blood pressure, and blood tests to assess glucose, cholesterol, inflammation, and other metabolic parameters. The findings will help determine whether one dietary pattern is more effective than others in improving short-term health outcomes in this population.

Read the detailed description

Detailed Description:

This randomized, controlled, parallel-group pilot clinical trial will evaluate the effects of three different hypocaloric dietary strategies on body composition, metabolic markers, and metabolic syndrome remission in adults with overweight or obesity.

Background and Rationale Overweight and obesity are highly prevalent in Europe and are associated with an increased risk of metabolic syndrome, cardiovascular disease, type 2 diabetes, and obesity-related cancers. Dietary interventions are a cornerstone in their management, but the optimal macronutrient composition for improving short-term metabolic outcomes remains unclear. This study investigates the comparative impact of a traditional Mediterranean diet, a Mediterranean low-carbohydrate diet, and a high-protein diet over a 12-week period.

Study Design A total of 45 participants aged 18-65 years with a body mass index (BMI) ≥25 kg/m² will be recruited through online advertisements and primary care referrals. After eligibility screening and informed consent, participants will be randomly allocated (1:1:1) to one of the three dietary intervention arms.

Intervention

All diets will be hypocaloric, aiming for a 20-25% reduction in individual energy requirements, and will differ in macronutrient distribution:

Mediterranean diet: 55% carbohydrates, 15% proteins, 30% fats.

Mediterranean low-carbohydrate diet: 40% carbohydrates, 25% proteins, 35% fats.

High-protein diet: 30% carbohydrates, 40% proteins, 30% fats.

Participants will be followed biweekly by qualified dietitians through in-person or phone consultations. They will receive personalized meal plans, nutritional education, and support materials to enhance adherence.

Assessments Anthropometric measures (BMI, fat mass, fat-free mass, waist and hip circumference) will be obtained at baseline and at 12 weeks using standardized protocols and validated equipment. Blood pressure will be measured with a calibrated automated device after a seated rest. Fasting blood samples will be collected in the morning for biochemical analyses, including glucose, HbA1c, insulin, lipid profile, uric acid, iron status, high-sensitivity C-reactive protein, fibrinogen, erythrocyte sedimentation rate, and liver enzymes.

Outcomes The primary outcome is the change in BMI after 12 weeks. Secondary outcomes include changes in body composition, metabolic and inflammatory biomarkers, and the proportion of participants meeting the International Diabetes Federation (IDF) criteria for metabolic syndrome at baseline and post-intervention.

Ethics and Dissemination The study protocol was approved by the Ethics Committee of Aragón (CEICA) (No. 13/2024) and will be conducted in accordance with the Declaration of Helsinki and current regulatory requirements. The findings will be disseminated through peer-reviewed publications and conference presentations.

Being tested
Mediterranean Diet, Mediterranean Low-Carbohydrate Diet, High-Protein Diet
Keywords
Randomized controlled trial, Mediterranean diet, Low-carbohydrate diet, High-protein diet, Dietary intervention, Metabolic health
Medical subject headings
Overweight, Obesity, Metabolic Syndrome

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Mediterranean DietOther

    A traditional Mediterranean diet providing approximately 55% of total energy from carbohydrates, 15% from protein, and 30% from fats. Emphasizes whole grains, vegetables, fruits, legumes, nuts, olive oil, moderate fish and poultry, and limited red meat, processed foods, and added sugars. Energy intake adjusted to achieve a 20-25% caloric deficit.

  • Mediterranean Low-Carbohydrate DietOther

    A Mediterranean-style diet with reduced carbohydrate content (40% of total energy from carbohydrates, 25% from protein, and 35% from fats). Retains core Mediterranean foods while limiting bread, pasta, rice, and other high-carb foods. Energy intake adjusted to achieve a 20-25% caloric deficit.

  • High-Protein DietOther

    A high-protein dietary pattern providing approximately 30% of total energy from carbohydrates, 40% from protein, and 30% from fats. Includes lean meats, poultry, fish, eggs, low-fat dairy, vegetables, nuts, and olive oil, with limited refined carbs and added sugars. Energy intake adjusted to achieve a 20-25% caloric deficit.

Study groups in NCT07314177
Study groupRoleWhat they receive
Arm 1: Mediterranean DietExperimentalParticipants assigned to this arm will follow a traditional Mediterranean diet providing approximately 55% of total energy from carbohydrates, 15% from protein, and 30% from fats. The diet emphasizes whole grains, fruits, vegetables, legumes, nuts, olive oil as the primary fat source, moderate fish and poultry intake, and limited consumption of red and processed meats, sweets, and sugary beverages. The prescribed energy intake represents a 20-25% caloric deficit based on individual estimated requirements. Participants receive personalized meal plans, nutritional education, and biweekly follow-up by a registered dietitian.
Receives: Other: Mediterranean Diet
Arm 2: Mediterranean Low-Carbohydrate DietExperimentalParticipants assigned to this arm will follow a Mediterranean-style diet with a reduced carbohydrate content, providing approximately 40% of total energy from carbohydrates, 25% from protein, and 35% from fats. The diet retains the core principles of the Mediterranean pattern, emphasizing vegetables, fruits, legumes, nuts, fish, and olive oil, while limiting bread, pasta, rice, and other high-carbohydrate foods. Energy intake is individualized to achieve a 20-25% caloric deficit. Participants receive personalized meal plans, nutritional education, and biweekly follow-up by a registered dietitian.
Receives: Other: Mediterranean Low-Carbohydrate Diet
Arm 3: High-Protein DietExperimentalParticipants assigned to this arm will follow a high-protein diet providing approximately 30% of total energy from carbohydrates, 40% from protein, and 30% from fats. Protein sources include lean meats, poultry, fish, eggs, and low-fat dairy products, combined with vegetables, nuts, and healthy fats such as olive oil. Refined carbohydrates and added sugars are limited. Energy intake is individualized to achieve a 20-25% caloric deficit. Participants receive personalized meal plans, nutritional education, and biweekly follow-up by a registered dietitian.
Receives: Other: High-Protein Diet

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Change in Body Mass Index (BMI, kg/m²) assessed by weight (Tanita MC-780MA bioimpedance scale) and height (Seca stadiometer) from baseline to 12 weeks

    BMI will be calculated as weight (kg) divided by height (m²). Weight will be measured without shoes using a Tanita MC-780MA multi-frequency bioelectrical impedance analyzer, and height will be measured using a calibrated Seca wall-mounted stadiometer.

    Measured: Baseline and week 12

Secondary outcomes (8)
  1. Change in Fat Mass Percentage (%) assessed by Tanita MC-780MA bioelectrical impedance analyzer from baseline to 12 weeks

    Fat mass percentage will be estimated using multi-frequency segmental bioelectrical impedance analysis (Tanita MC-780MA).

    Measured: Baseline and week 12

  2. Change in Fat-Free Mass Percentage (%) assessed by Tanita MC-780MA bioelectrical impedance analyzer from baseline to 12 weeks

    Fat-free mass percentage will be estimated using multi-frequency segmental bioelectrical impedance analysis (Tanita MC-780MA).

    Measured: Baseline and week 12

  3. Change in Metabolic Syndrome Status (yes/no) defined by IDF criteria from baseline to 12 weeks

    Metabolic syndrome will be diagnosed according to the International Diabetes Federation (IDF) criteria, requiring ≥3 of the following: elevated waist circumference, elevated triglycerides, reduced HDL cholesterol, elevated blood pressure, or elevated fasting glucose.

    Measured: Baseline and week 12

  4. Change in glycated hemoglobin (HbA1c, %) from baseline to 12 weeks

    HbA1c levels will be measured in fasting venous blood samples using high-performance liquid chromatography (HPLC), following standardized laboratory procedures.

    Measured: Baseline and week 12

  5. Change in serum total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides (mg/dL) from baseline to 12 weeks

    Serum lipids will be determined from fasting blood samples analyzed enzymatically in a certified laboratory. Results will be reported in mg/dL for each parameter.

    Measured: Baseline and week 12

  6. Change in fasting glucose (mg/dL) from baseline to 12 weeks

    Fasting glucose concentration will be measured in venous blood samples collected early in the morning under standardized fasting conditions. Glucose levels will be quantified using validated automated enzymatic assays in a certified clinical laboratory.

    Measured: Baseline and week 12

  7. Change in high-sensitivity C-reactive protein (hs-CRP, mg/dL) from baseline to 12 weeks

    Serum hs-CRP concentrations will be measured in fasting venous blood samples collected in the morning and analyzed using a standardized high-sensitivity immunoassay in a certified clinical laboratory. Values will be reported in mg/dL.

    Measured: Baseline and week 12

  8. Change in serum uric acid (mg/dL) from baseline to 12 weeks

    Serum uric acid will be measured by an enzymatic colorimetric method in a certified laboratory. Results will be reported in mg/dL.

    Measured: Baseline and week 12

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted2 Jan 2026
  2. Study start8 Sep 2024
  3. Primary completion20 Apr 2025
  4. Study completion25 Jun 2025

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Other
Allocation
Randomised
Intervention model
Parallel groups
Masking
None (open label)
Enrolment
45 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07314177
Sponsor's protocol ID
PI24/171
Other IDs
CEICA-13/2024-PI24-171
Status last verified
Dec 2025
First submitted
28 Aug 2025
Last updated
2 Jan 2026
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Questions about this trial

What is this clinical trial studying?

A study testing Mediterranean Diet, Mediterranean Low-Carbohydrate Diet and High-Protein Diet in people with Overweight (BMI > 25) and Obesity &Amp; Overweight, run by Consorcio Centro de Investigación Biomédica en Red (CIBER) at 1 site in Spain.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 6 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 2 Jan 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Spain. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Change in Body Mass Index (BMI, kg/m²) assessed by weight (Tanita MC-780MA bioimpedance scale) and height (Seca stadiometer) from baseline to 12 weeks (time frame: Baseline and week 12). It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 2 Jan 2026; AzTrials last refreshed its copy on 26 Oct 2026.

Free account

Keep searching with a free account

You’ve used your 3 free searches for this session. Log in or create a free AzTrials account to keep searching clinical trials and save the ones you want to follow.

Create a free accountLog in