Effect of GLP-1 Receptor Agonists on Body Composition in Obesity: The Role of Dietary Protein Consumption in Muscle Mass Maintenance

NCT07495904 | Recruiting

• 2 other identifiers: 159302Protocol No. 44248
• Study Type: interventional
• Target: 130
• Locations: 1 country
• Sites: 2

Brief Summary

This study investigates how weight-loss medications, specifically GLP-1 receptor agonists, affect body composition, with a special focus on preserving muscle mass in adults with obesity. While these medications are highly effective for weight loss, they can sometimes lead to an unwanted loss of valuable muscle mass (a condition that can lead to sarcopenia). To explore how to prevent this, researchers are conducting a 3- to 6-month randomized controlled trial involving adults aged 30 to 65 years with a BMI greater than 30 kg/m². Participants who are receiving GLP-1 medications will be randomly assigned to one of two groups: one group will receive the standard medication treatment alone, while the other group will receive the medication along with specific dietary guidance focused on increasing daily protein intake.

Conditions

Obesity

Keywords

Body composition; pharmacologically induced weight loss; GLP-1 receptor agonists; muscle mass; dietary protein

Outcome Measures

Primary Outcomes (1)

• Change from Baseline in Muscle Mass

  Evaluation of the change in Muscle Mass using a multi-compartment body composition model (4C/5C). This gold-standard approach integrates data from Underwater Weighing (Body Density), Dual-Energy X-ray Absorptiometry (DEXA, for Bone Mineral Content), and Bioelectrical Impedance Spectroscopy (BIS, for Total Body Water) to provide a precise estimation of muscle mass. Results will be reported in kilograms (kg)

  Baseline and End of Intervention (up to 24 weeks)

Secondary Outcomes (5)

• Change from Baseline in Body Composition Parameters

  Baseline, End of Intervention (up to 24 weeks), and at 6 months post-intervention

• Change from Baseline in Biochemical and Urinary Markers

  Baseline, End of Intervention (up to 24 weeks), and at 6 months post-intervention

• Long-term Weight Maintenance Efficiency

  From End of Intervention (up to 24 weeks) to 6 months post-intervention

• Change from Baseline in Sarcopenia Risk

  Baseline, End of Intervention (up to 24 weeks), and at 6 months post-intervention

• Change from Baseline in Energy and Macronutrient Intake

  Baseline, End of Intervention (up to 24 weeks), and at 6 months post-intervention

Study Arms (2)

GLP-1 + Standard Diet

ACTIVE COMPARATOR

Participants will receive GLP-1 treatment alongside standard nutritional counseling based on the Mediterranean diet pattern, provided within the framework of usual clinical practice.

Behavioral: Control (Standard Mediterranean Diet Counseling)

GLP-1 + High Protein Diet

EXPERIMENTAL

Participants will receive GLP-1 treatment along with a specialized dietary intervention featuring individualized guidelines aimed at increasing daily protein intake.

Behavioral: High Protein Dietary Intervention

Interventions

High Protein Dietary Intervention BEHAVIORAL

Individualized dietary guidelines focusing on increased protein consumption to preserve muscle mass during weight loss.

GLP-1 + High Protein Diet

Control (Standard Mediterranean Diet Counseling) BEHAVIORAL

Standard nutritional counseling based on the Mediterranean diet pattern as part of usual clinical practice.

GLP-1 + Standard Diet

Eligibility Criteria

• Age: 30 Years - 65 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Adults 30-65 years old
• BMI: ≥30 kg/m²
• Signed Informed Consent

You may not qualify if:

• A. Metabolic and Medical Conditions:
• Uncontrolled type 2 diabetes (HbA1c \> 9.0%)
• Known cardiovascular disease (e.g., coronary artery disease, heart failure NYHA 3-4)
• Chronic kidney disease stage 4-5 (GFR \<60 ml/min)
• Liver disease (known hepatitis, ALT ≥ 3 or total bilirubin ≥ 2 times ULN)
• Inflammatory bowel disease
• Celiac disease
• History of pancreatitis
• Any disorder potentially causing malabsorption
• Active cancer or history of malignancy within the past 3 years
• Psychiatric disorders affecting adherence or assessment B. Medication and Supplement Use
• Chronic use of medications affecting metabolism or body composition (e.g., corticosteroids, anti-obesity drugs)
• Use of anti-inflammatory or antioxidant medications
• Use of probiotics, prebiotics, or laxatives within the last month
• Unstable medication regimen (changes within the past 3 months)

Sponsors & Collaborators

• Hellenic Mediterranean University: lead
• University General Hospital of Heraklion: collaborator

Study Sites (2)

1st Department of Internal Medicine, University General Hospital of Heraklion

Heraklion, Greece

RECRUITING

Human Dietetics & Body Composition Laboratory, Department of Nutrition and Dietetics Sciences, Hellenic Mediterranean University

Heraklion, Greece

RECRUITING

MeSH Terms

Conditions

Obesity

Condition Hierarchy (Ancestors)

Overweight; Overnutrition; Nutrition Disorders; Nutritional and Metabolic Diseases; Body Weight; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Study Officials

• Christopher Papandreou

  Hellenic Mediterranean University

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Ioanna Charalampidou

CONTACT

+302810379242; icharalampidou@hmu.gr

Christopher Papandreou

CONTACT

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Assistant Professor, Department of Nutrition & Dietetics Sciences

Study Record Dates

• First Submitted: March 23, 2026
• First Posted: March 27, 2026
• Study Start: March 30, 2026
• Primary Completion (Estimated): March 30, 2028
• Study Completion (Estimated): January 30, 2029
• Last Updated: April 2, 2026

Record last verified: 2026-03

Data Sharing

• IPD Sharing: Will not share

Locations

GR (2)