ObesityNCT07611201
The Effects of GLP-1 Receptor Agonists on Chemosensory Function and Ingestive Behavior
An observational study of Obesity and Overweight, run by Purdue University at 1 site in United States.
Trial 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. Read more about this study
- Who is it for?
- Ages 18 to 65 yearsHealthy volunteers can take part
- Conditions the study is for
- Obesity, Overweight, Taste Perception
- How many people
- 90 participants
- Where
- 1 siteUnited States
- Study dates
- 20 Feb 2025to 4 May 2026
- Phase
- Observational
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 18 to 65 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
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.
Who may be able to join
- 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.
Who cannot join
- 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.
Trial locations and contacts
1 site in 1 country.
About this study
Official title: The Effects of GLP-1 Receptor Agonists on Sensory Systems and Ingestive Behavior
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:
Read more
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.
Read the detailed description
This cross-sectional study examines associations between GLP-1 receptor agonist use, chemosensory function, and ingestive behavior in adults. People enrolled in the study are classified into groups based on GLP-1 receptor agonist use status and duration of use: adults who are not currently taking a GLP-1 receptor agonist but may be eligible to use one, adults taking a GLP-1 receptor agonist for approximately 1 month, and adults taking a GLP-1 receptor agonist for approximately 6 months.
GLP-1 receptor agonist use is not assigned by the research team. People who are taking these medications are using them as part of their regular medical care. The study team does not prescribe, administer, or change GLP-1 receptor agonist treatment.
Study procedures include assessments of taste and smell function, food preferences, food reward, appetite, food cravings, food cue responsivity, attentional responses to food cues, and salivary responses to a food cue. Outcomes will be compared across groups to explore whether GLP-1 receptor agonist use and duration of use are associated with differences in chemosensory function and ingestive behavior.
- 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
- Medical subject headings
- Obesity, Overweight, Anosmia, Feeding Behavior, Food Preferences
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| 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. |
What is being measured
The primary outcome is the main question the study is designed to answer.
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.
Measured: 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.
Measured: 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.
Measured: 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.
Measured: 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.
Measured: 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.
Measured: During study participation, up to 2 weeks
Secondary outcomes (5)
Food Preferences
Food preferences will be assessed using the Leeds Food Preference Questionnaire. Participants will view food images and rate how much they like and want to eat each food item. Ratings will be used to assess explicit liking and wanting for foods.
Measured: During study participation, up to 2 weeks
Attentional Bias to Food Cues
Attentional bias to food cues will be assessed using a Food Stroop Task. Participants will view food-related and non-food words and respond to the color of each word while ignoring the meaning of the word. Response patterns will be used to assess attentional bias toward food-related cues.
Measured: During study participation, up to 2 weeks
Questionnaire-Based Measures of Food Cravings, Food Cue Responsivity, Food Noise, and Eating Behavior
Questionnaire-based measures will be used to assess food cravings, food cue responsivity, food-related intrusive thoughts, perceived food reward, and eating behavior. Participants will complete the Food Cue Responsivity Scale, the Modified Trait and State Food Cravings Questionnaires, the Power of Food Scale, the Food Noise Questionnaire, and the Reasons Individuals Stop Eating Questionnaire. These questionnaires will assess sensitivity to food-related cues, typical and momentary food cravings, food-related intrusive thoughts, perceived responsiveness to the food environment, and reasons for stopping eating, including motivations and physical cues related to meal termination and satisfaction.
Measured: During study participation, up to 2 weeks
Dietary Intake
Dietary intake will be assessed using ASA24, the Automated Self-Administered 24-Hour Dietary Assessment Tool. Participants will complete three 24-hour dietary recalls on different days, including two weekdays and one weekend day, to report foods and beverages consumed over the previous 24 hours.
Measured: During study participation, up to 2 weeks
Cephalic-Phase Salivary Response
Cephalic-phase salivary response will be assessed by measuring saliva production at baseline and during exposure to a food cue. Saliva will be collected during a baseline period and again while participants simulate eating a food item by focusing on its smell, taste, and texture. Saliva will be collected in graduated tubes and weighed to quantify salivary output. Change in salivation from baseline to food cue exposure will be compared across groups.
Measured: During study participation, up to 2 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted28 May 2026
- Study start20 Feb 2025
- Primary completion4 May 2026
- Study completion4 May 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (2)Papers the sponsor has linked to this study.
- Other trials for ObesityStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Cross-sectional
- Enrolment
- 90 participants (actual)
Sponsor and investigators
- Lead sponsor
- Purdue University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Richard Mattes, Purdue University
- Investigators
- Richard D Mattes, PhD, RD, MPH, Principal investigator, Purdue University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07611201
- Sponsor's protocol ID
- IRB-2024 - 1407
- Status last verified
- May 2026
- First submitted
- 14 May 2026
- Last updated
- 28 May 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Individual participant data will not be shared because the current IRB-approved protocol does not include a formal plan for external individual participant data sharing. Study data will be maintained in de-identified form, and identifiers/code keys will be stored separately and destroyed according to the approved protocol. De-identified data may be used by the study team for approved secondary analyses, but individual participant data will not be made publicly available or shared externally.
Publications
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.
PubMed 31665455Rutigliani G, Mattes RD. The Effects of Glucagon-Like Peptide-1 Receptor Agonists on Chemosensory Function and Ingestive Behavior. Physiol Behav. 2026 Aug 25:115486. doi: 10.1016/j.physbeh.2026.115486. Online ahead of print.
PubMed 42641845