Changes in Taste and Eating Habits Associated With GLP-1 Agonists in Weight Loss Patients (GLP1-TASTE)

Changes in Taste Perception, Eating Habits, and Other Behavioral Aspects Associated With the Use of GLP-1 Receptor Agonists in Patients Undergoing Weight Loss Treatment: A Retrospective Observational Study.

This observational retrospective study aims to evaluate changes in taste perception, eating habits, and behavioral aspects in adults treated with GLP-1 receptor agonists for weight loss. Participants include adults aged 18-60 receiving treatment at specialized nutrition centers in Italy. Data are collected from clinical records, dietary questionnaires, and metabolic assessments before and after at least 12 weeks of GLP-1 agonist treatment. The study's primary goal is to understand how these treatments affect food preferences and taste perception. Secondary outcomes include changes in body weight, body composition, gastrointestinal side effects, and treatment adherence. All data are anonymized and collected according to ethical guidelines.

Study Overview

• Status: Recruiting
• Conditions: Weight Loss; Obesity & Overweight; Taste Alterations; Eating Behavior Changes

Detailed Description

This retrospective observational study investigates changes in taste perception, eating habits, and other behavioral aspects associated with the use of GLP-1 receptor agonists in patients undergoing treatment for weight loss. The study includes adults aged 18-60 years who have been treated at specialized nutrition centers in Italy during 2025-2026. Data are collected retrospectively from clinical records, dietary questionnaires, bioimpedance analysis for body composition, and metabolic assessments conducted before and after at least 12 weeks of treatment with GLP-1 agonists such as semaglutide or tirzepatide.

The primary objective is to evaluate the impact of GLP-1 agonist treatment on food preferences and taste perception changes. Secondary objectives include quantifying changes in body weight, body mass index (BMI), and body composition (fat mass and lean mass), assessing gastrointestinal side effects, measuring total energy expenditure and physical activity variations, and estimating treatment adherence and discontinuation reasons.

Data collection involves anonymized extraction of demographic, anthropometric, clinical, dietary, and behavioral information in accordance with GDPR and ethical guidelines. The analysis is performed using statistical methods including paired t-tests, Wilcoxon tests, and regression models adjusted for age, sex, baseline BMI, diabetes status, and concomitant medications.

This study is non-profit and does not involve additional costs or interventions beyond routine clinical care. Ethical approval is pending and will be obtained before the study initiation. All procedures will comply with local regulations and ethical guidelines.

• Study Type: Observational
• Enrollment (Estimated): 150

Contacts and Locations

• Study Contact: Name: Mauro Lombardo, MD; Phone Number: +393899740197; Email: mauro.lombardo@uniroma5.it

Study Locations

• Italy
  • Rome, Italy, 00166
    • Recruiting
    • Department for the Promotion of Human Science and Quality of Life San Raffaele Open University
    • Contact: Alessandra Feraco, PhD; Phone Number: +39 339 869 8874; Email: alessandra.feraco@uniorma5.it
  • Rome, Italy, 00166
    • Active, not recruiting
    • San Raffaele Open University
  • Rome, Italy, 00166
    • Recruiting
    • San Raffaele Open University
    • Contact: Mauro Lombado; Phone Number: +393899740197
  • Italy
    • Roma, Italy, Italy, 00166
      • Recruiting
      • San Raffaele Open University
      • Contact: Stefania Supino, PhD; Phone Number: +39 800 128 606; Email: stefania.supino@uniroma5.it

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Adults with obesity receiving GLP-1 agonist treatment at specialized nutrition centers in Italy, assessed retrospectively.

Description

Inclusion: Adults aged 18-60 years diagnosed with obesity and undergoing treatment with GLP-1 receptor agonists such as semaglutide or tirzepatide. Must have clinical records and dietary data available for at least 12 weeks of treatment.

Exclusion: Patients with conditions affecting taste independent of GLP-1 treatment, severe comorbidities, or inability to provide consent and data.

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

GLP-1 Agonist Treated Patients; This cohort includes adult patients aged 18-60 who have been treated with GLP-1 receptor agonists such as semaglutide or tirzepatide for weight loss in specialized nutrition centers in Italy. The study collects retrospective data on changes in taste perception, eating habits, body composition, and treatment adherence over a minimum duration of 12 weeks of therapy. No interventional treatments are administered as part of this observational study.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in taste perception and food preferences	Assessment of patients' taste perception changes and shifts in eating habits using validated questionnaires and behavioral surveys.	From baseline to 12 weeks after GLP-1 agonist treatment

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in body weight	Measured in kilograms to assess weight loss effectiveness.	From baseline to 12 weeks after treatment
Gastrointestinal side effects	Recording of nausea, vomiting, diarrhea, or other GI symptoms via patient reports.	Throughout the treatment period
Treatment adherence	Assessment of continued use and discontinuation reasons of GLP-1 agonists.	Throughout the study duration

Collaborators and Investigators

• Sponsor: San Raffaele Telematic University

Publications and helpful links

General Publications

• Wilding JPH, Batterham RL, Calanna S, Davies M, Van Gaal LF, Lingvay I, McGowan BM, Rosenstock J, Tran MTD, Wadden TA, Wharton S, Yokote K, Zeuthen N, Kushner RF; STEP 1 Study Group. Once-Weekly Semaglutide in Adults with Overweight or Obesity. N Engl J Med. 2021 Mar 18;384(11):989-1002. doi: 10.1056/NEJMoa2032183. Epub 2021 Feb 10.

Study record dates

Study Major Dates

• Study Start (Actual): December 1, 2025
• Primary Completion (Estimated): January 1, 2027
• Study Completion (Estimated): January 1, 2028

Study Registration Dates

• First Submitted: November 13, 2025
• First Submitted That Met QC Criteria: November 13, 2025
• First Posted (Actual): November 14, 2025

Study Record Updates

• Last Update Posted (Actual): April 28, 2026
• Last Update Submitted That Met QC Criteria: April 22, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: Weight loss; Eating habits; Observational study; Obesity treatment; GLP-1 agonists; Taste perception
• Additional Relevant MeSH Terms: Nutrition Disorders; Overnutrition; Body Weight; Body Weight Changes; Pathological Conditions, Signs and Symptoms; Behavior; Nutritional and Metabolic Diseases; Signs and Symptoms; Behavior, Animal; Overweight; Obesity; Weight Loss; Feeding Behavior
• Other Study ID Numbers: GLP1-TASTE

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED
• IPD Plan Description: At this time, there is no definitive plan to share individual participant data. Once the study is completed and data analysis finalized, decisions about data sharing will be made in accordance with institutional policies, ethical guidelines, and participant consent. If data sharing is pursued, de-identified datasets and supporting documents may be made available to qualified researchers upon reasonable request.

Drug and device information, study documents

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