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.

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.

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.

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

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.