The Effects of GLP-1 Receptor Agonists on Chemosensory Function and Ingestive Behavior

NCT07611201 | Completed

• 1 other identifier: IRB-2024 - 1407
• Study Type: observational
• Target: 90
• Locations: 1 country
• Sites: 1

Brief Summary

The goal of this study is to explore whether of GLP-1 receptor agonist use is associated with differences in taste, smell, food preferences, appetite, food cravings, and responses to food cues in adults. The study includes adults who are not currently taking a GLP-1 receptor agonist but may be eligible to use one, and adults who are already taking a GLP-1 receptor agonist as part of their regular medical care for approximately 1 month or approximately 6 months. The main questions it aims to answer are: Are taste and smell function different among adults who are not taking a GLP-1 receptor agonist and adults who have been taking one for different lengths of time? Are food preferences, appetite, food cravings, food reward, attention to food cues, and salivary responses to food cues different among these groups? Researchers will compare adults not currently taking a GLP-1 receptor agonist with adults taking a GLP-1 receptor agonist for approximately 1 month or approximately 6 months. The research team will not prescribe, assign, or provide GLP-1 receptor agonist medications. People in the study will attend two in-person study visits, complete taste and smell tests, complete food preference and computer-based tasks, and provide saliva samples during a food cue task. Questionnaires about appetite, cravings, food cues, and eating behavior will be completed at home over approximately 2 weeks.

Conditions

Obesity; Overweight; Taste Perception; Olfaction; Eating Behavior; Appetite

Keywords

GLP-1 receptor agonists; taste; smell; olfaction; food preferences; food craving; appetite; Food cue responsivity; Salivary response

Outcome Measures

Primary Outcomes (6)

• Taste Detection Thresholds

  Taste detection thresholds will be assessed for sweet, salty, sour, and bitter stimuli (sucrose, sodium chloride, citric acid, and urea, respectively) using a two-alternative forced-choice staircase procedure, in which participants identify which of two samples contains the taste stimulus. Separate outcomes will be reported for each taste quality: sweet, salty, sour, and bitter. For each taste quality, the threshold will be calculated as the geometric mean concentration at which the stimulus is reliably detected and will be reported in mmol/L. Lower threshold values indicate greater taste sensitivity.

  During study participation, up to 2 weeks

• Suprathreshold Taste Intensity

  Suprathreshold taste intensity will be assessed for sweet, salty, sour, and bitter stimuli (sucrose, sodium chloride, citric acid, and urea, respectively) using the general Labeled Magnitude Scale. Separate outcomes will be reported for each taste quality and stimulus concentration. For each taste quality, participants will rate the perceived intensity of suprathreshold stimulus concentrations. The scale ranges from 0 to 100, with 0 anchored by "no sensation" and 100 anchored by "strongest imaginable sensation of any kind." Higher scores indicate greater perceived taste intensity.

  During study participation, up to 2 weeks

• Taste Hedonics

  Taste hedonics will be assessed using a food modification task in which participants create preferred concentrations for sweet, salty, sour, bitter, and fatty stimuli. Separate outcomes will be reported for each stimulus type: sweet, salty, sour, bitter, and fatty. For each stimulus type, the outcome will be the preferred concentration selected by the participant. Higher values indicate preference for a higher concentration of that stimulus and do not necessarily indicate a better or worse outcome.

  During study participation, up to 2 weeks

• Fat Taste Intensity Rating

  Fat taste perception will be assessed using edible strips containing different concentrations of linoleic acid. Participants will rate the perceived intensity of each strip using the general Labeled Magnitude Scale. Separate outcomes will be reported for each linoleic acid concentration. The scale ranges from 0 to 100, with 0 anchored by "no sensation" and 100 anchored by "strongest imaginable sensation of any kind." Higher scores indicate greater perceived fat taste intensity.

  During study participation, up to 2 weeks

• ArOMa-T Olfactory Test Performance

  Olfactory function will be assessed using the ArOMa-T test. Participants will smell odor stimuli and provide computer-based responses to questions assessing olfactory performance. The outcome will be the ArOMa-T test score, with higher scores indicating better olfactory performance.

  During study participation, up to 2 weeks

• SCENTinel Olfactory Test Performance

  Olfactory function will be assessed using the SCENTinel test. Participants will smell odor stimuli and provide computer-based responses to questions assessing odor detection, odor identification, odor intensity, and odor pleasantness. Separate outcomes will be reported for each SCENTinel component. Higher scores indicate better odor detection or identification performance, greater perceived odor intensity, or greater perceived odor pleasantness, depending on the component assessed.

  During study participation, up to 2 weeks

Secondary Outcomes (5)

• Food Preferences

  During study participation, up to 2 weeks

• Attentional Bias to Food Cues

  During study participation, up to 2 weeks

• Questionnaire-Based Measures of Food Cravings, Food Cue Responsivity, Food Noise, and Eating Behavior

  During study participation, up to 2 weeks

• Dietary Intake

  During study participation, up to 2 weeks

• Cephalic-Phase Salivary Response

  During study participation, up to 2 weeks

Study Arms (3)

Pre-use / Not Currently Taking GLP-1RA

Adults who are not currently taking a GLP-1 receptor agonist but may be eligible to use one based on body weight criteria (BMI \> 30). Participants in this group are not assigned to GLP-1 receptor agonist treatment by the study team.

Approximately 1 Month GLP-1RA Use

Adults who have been taking a GLP-1 receptor agonist as part of their regular medical care for approximately 1 month. GLP-1 receptor agonist use is not assigned, prescribed, or modified by the study team.

Approximately 6 Months GLP-1RA Use

Adults who have been taking a GLP-1 receptor agonist as part of their regular medical care for approximately 6 months. GLP-1 receptor agonist use is not assigned, prescribed, or modified by the study team.

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Adults aged 18 to 65 years with a Body Mass Index (BMI) greater than 30 kg/m² will be recruited. The study population includes individuals who are eligible to take GLP-1 receptor agonists but have not yet started treatment, and individuals who have been taking GLP-1 receptor agonists for weight management for approximately 1 month or approximately 6 months as part of their regular medical care. Participants will be recruited from the general population and through healthcare providers at IU Health.

You may qualify if:

• Ages 18 to 65 years.
• Any sex or gender.
• Body Mass Index (BMI) \>30 kg/m².
• Stable medication use, excluding weight management medications other than GLP-1 receptor agonist use as part of regular medical care.
• Eligible to take GLP-1 receptor agonists but not yet started treatment, or currently taking GLP-1 receptor agonists for weight management for approximately 1 month (±0.5 months) or approximately 6 months (±0.5 months).
• No known sensitivity or allergy to study solutions or foods, including sweet solutions, salty solutions, sour solutions, bitter solutions, fatty stimuli, common food flavors used in testing, milk, and fruit-flavored beverages.

You may not qualify if:

• Younger than 18 years or older than 65 years.
• Previous bariatric surgery or planned bariatric surgery within the next year.
• Sensitivity or allergy to study foods, taste solutions, odor stimuli, or food-related test materials.

Sponsors & Collaborators

• Purdue University: lead

Study Sites (1)

Purdue University

West Lafayette, Indiana, 47906, United States

Location

Related Publications (1)

• Kadouh H, Chedid V, Halawi H, Burton DD, Clark MM, Khemani D, Vella A, Acosta A, Camilleri M. GLP-1 Analog Modulates Appetite, Taste Preference, Gut Hormones, and Regional Body Fat Stores in Adults with Obesity. J Clin Endocrinol Metab. 2020 May 1;105(5):1552-63. doi: 10.1210/clinem/dgz140.

  PMID: 31665455 BACKGROUND

MeSH Terms

Conditions

Obesity; Overweight; Anosmia; Feeding Behavior; Food Preferences

Condition Hierarchy (Ancestors)

Overnutrition; Nutrition Disorders; Nutritional and Metabolic Diseases; Body Weight; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Olfaction Disorders; Sensation Disorders; Neurologic Manifestations; Nervous System Diseases; Behavior, Animal; Behavior

Study Officials

• Richard D Mattes, PhD, RD, MPH

  Purdue University

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: CROSS SECTIONAL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Distinguished Professor

Study Record Dates

• First Submitted: May 14, 2026
• First Posted: May 28, 2026
• Study Start: February 20, 2025
• Primary Completion: May 4, 2026
• Study Completion: May 4, 2026
• Last Updated: May 28, 2026

Record last verified: 2026-05

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)