ObesityNCT04714892
Mechanisms Underlying Individual Variations of Taste and Smell in Obesity
An observational study of Obesity, run by National Institute on Alcohol Abuse and Alcoholism (NIAAA) at 1 site in United States.
Trial summary
Background: Changes to the sense of taste or smell can change eating behavior. This may contribute to obesity. Researchers want to see how taste and smell perceptions that affect food choices may differ between people with obesity and without obesity. Read more about this study
- Who is it for?
- Ages 18 to 65 yearsHealthy volunteers can take part
- Conditions the study is for
- Obesity
- How many people
- 350 participants
- Where
- 1 siteUnited States
- Study dates
- 11 May 2022to 31 Dec 2026
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
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: Participants will be recruited from the Washington DC metropolitan area and vicinity.
Who may be able to join
- In order to be eligible to participate in this study, an individual must meet all of the following criteria:
- Males and females between 18 to 65 years of age. Due to documented knowledge that taste and smell changes with age, we will limit the cohort within this age range.
- BMI between 18.5 and 29.9 kg/m^2 for healthy controls or between 30 and 39.9 kg/m^2 for obese subjects at screening
- Fasted plasma glucose levels between 68-126 mg/dl or per Clinical Center ranges, and hemoglobin A1C<6.5%
- Able to provide his/her own consent
- Able to understand the protocol, as shown by scoring a 6 out of 6 on a consent quiz
Who cannot join
- An individual who meets any of the following criteria will be excluded from participation in this study:
- Because type-2 diabetic subjects have blunted taste responses, subjects with diagnosis of type II diabetes will be excluded.
- Hypoglycemic drug intake.
- Weight change of more than 15 pounds in the 6 months prior to screening
- Positive pregnancy test, currently pregnant or breastfeeding.
- Currently using any of the following medications: steroidal or nonsteroidal antiinflammatory medications, medications known to inhibit taste response (GLP1 agonists), antiepileptic or antidepressant agents, glucocorticoids, or antibiotics.
Show all 19Show fewer
- Received a diagnosis by a medical professional of morbid obesity, liver or renal disease.
- Individuals with current heavy drinking. Women who drink 4 drinks or more in one occasion and 7 drinks in a week. Men who drink 5 drinks or more in one occasion and more than 14 drinks a week.
- Use of tobacco products or illicit drugs (as determined by urine drug screen and/or history/physical exam) in the last 30 days.
- Currently have an uncontrolled medical disorder (i.e., gastrointestinal, endocrine, cardiac, psychiatric).
- Any self-reported history of chronic rhinitis, eating disorder (including binge eating), chronic upper respiratory infection, chronic allergic rhinitis, or nasal polyps in the last 6 months of screening, or current daily use of nasal sprays.
- Abnormal complete blood count (CBC): White Blood Cell Count < 4 or > 10 K/uL, Red Blood Cell Count < 4 or > 7 M/uL, Hemoglobin < 12 g/dL for females or < 13 g/dL for males or any clinical signs/symptoms that indicate iron deficiency anemia per clinician's judgment at screening [National Heart, Lung and Blood Institute (NHLBI) definition (Anemia - Iron-Deficiency Anemia, Diagnosis; NHLBI, NIH)].
- Bariatric surgery within the last 12 months of screening.
- History of cancer (e.g., head and neck cancer) and/or history of cancer treatment (e.g., radiotherapy to the head and neck area or chemotherapy).
- Altered cranial nerves identified by neurological evaluation during physical exam (screening visit).
- Currently experiencing temporary change/loss of taste and/or smell.
- Persistent loss of taste and/or smell due to COVID-19 or other reasons.
- Unable to read and understand English. Since all self-report measures are in English only, participants need to be able to read and understand the English language.
- NIAAA employees/staff or subordinates/relatives/co-workers of NIAAA employees/staff or study investigators.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Paule V Joseph, C.R.N.P. contact
United States1 site, 1 recruiting
- Recruiting
National Institutes of Health Clinical Center
Bethesda, Maryland, 20892
For more information at the NIH Clinical Center contact Office of Patient Recruitment (OPR), 800-411-1222 ext. TTY8664111010, prpl@cc.nih.gov
About this study
Background:
Changes to the sense of taste or smell can change eating behavior. This may contribute to obesity. Researchers want to see how taste and smell perceptions that affect food choices may differ between people with obesity and without obesity.
Read more
Objective:
To understand the role that senses of taste and smell play in food intake.
Eligibility:
Adults ages 18-65 with obesity and without obesity
Design:
Participants will be screened with a medical history and physical exam. They will have a neurological and sensory exam. They will give blood and urine samples. They will be checked for previous SARS-CoV-2 infection. They will complete questionnaires about their eating habits, alcohol use, and smoking history.
Participants will have 2 study visits.
Participants will give stool, urine, blood, hair, nasal, and saliva samples. These samples will be used for gene testing.
Participants will have their weight, height, and hip and waist circumference measured. They will have an imaging scan that measures body composition.
Participants will complete questionnaires about their health, eating habits, and food preferences.
Participants will have taste tests and smell tests. They will have sensory tests to assess their response to stimuli.
Participants will have a dietary assessment. They will complete a food diary and a diet history questionnaire.
Participants will get a meal to eat. Data will be collected about their experience.
Participants will complete a sleep diary and wear a watch to measure their activity....
Read the detailed description
Study Description:
This study involves comparison of taste and smell measures between obese and non-obese individuals. Taste and smell perceptions will be assessed in terms of their influence in food intake and food choices. We hypothesize that obesity negatively affects taste and smell perception thus affecting eating behavior.
Objectives:
Obesity is a major public health concern in America. An unhealthy diet is a recognized risk factor for the development of obesity. Public health efforts to modify eating behaviors have had limited success. Not only does an unhealthy diet contribute to obesity, but it can also lead to changes in gut microbiota that likely result in inflammation and changes in transcriptomic activity. Taste and smell perceptions, which can influence food choices and food consumption, may differ between obese and non-obese individuals. Currently, little is known about the underlying mechanisms causing variations in taste and smell systems in individuals with obesity, which limits the interventions currently available to address this critical issue. Findings from this study can be used to design more effective interventions for the prevention and treatment of obesity, to identify targets and strategies for countermeasures to prevent or improve obesity and its comorbidities, and to suggest ways to enhance dietary interventions. Moreover, findings will foster new lines of investigation for reducing risk of diet related conditions and for developing novel behavioral and pharmacological avenues of treatment and prevention. The proposed research is aligned with the overall mission of the National Institutes of Health to promote health and disease prevention. The findings from this study will ultimately lead to the development of personalized interventions for individuals with obesity and concurrent taste and smell alterations. Lastly, approaches included in this proposal are innovative and highly applicable to other complex health phenomena in which biological variations in inflammation and taste and smell perception impact an individual s health.
Endpoints:
Primary Endpoint: The primary dependent measures for this study are taste and olfaction measures.
Secondary Endpoints: Secondary measures include inflammatory markers, exosomes, microbiota, gene expression, DNA methylation, biological measures and personal factors.
- Conditions
- Obesity
- Keywords
- chemosensation, Olfaction, Diet, obese, Perception, Natural History
- Medical subject headings
- Obesity, Anosmia
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 |
|---|---|---|
| Healthy control | BMI of 18.5-29.9 kg/m^2 | |
| Obese | BMI of 30-39.9 kg/m^2 |
What is being measured
The primary outcome is the main question the study is designed to answer.
Measures of taste and smell, and eating behavior
Compare individuals with obesity to healthy controls in measures of taste and smell and eating behaviors.
Measured: At enrollment
Secondary outcomes (4)
Inflammatory markers, exosome and microbiota
Compare individuals with obesity to healthy controls in measures of inflammation (cytokines and chemokines) in circulating blood, and neuronally-derived exosomes from plasma, and in the oral and nasal microbiome composition and its metabolites.
Measured: At enrollment
Gene expression, DNA methylation, taste and smell measures
Compare individuals with obesity to healthy controls on transcriptomic and epigenomic profiles in monocytes, based on gene expression (RNA sequencing) and whole genome DNA methylation, to identify associated variations in taste and smell perception.
Measured: At enrollment
Biological measures, personal factors, taste and smell measures
Examine how biological measures of inflammation and genomic profiles relate to taste and smell variations based on personal factors (i.e., race, age, and sex) and other factors (i.e., diet) within the obese group
Measured: At enrollment
Severity of neuropsychological sysmptoms such as fatigue, anxiety, depression, sleep; perceived stress, pain and QoL
Evaluate symptoms clusters with alterations in taste and smell and identify phenotypic symptoms characteristics
Measured: At enrollment
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted20 Jan 2021
- Study start11 May 2022
- Primary completion30 Dec 2026 (estimated)
- Study completion31 Dec 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- 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
- Case-control
- Time perspective
- Cross-sectional
- Enrolment
- 350 participants (estimated)
Sponsor and investigators
- Lead sponsor
- National Institute on Alcohol Abuse and Alcoholism (NIAAA)
- Sponsor type
- US National Institutes of Health
- Responsible party
- Sponsor
- Investigators
- Paule V Joseph, C.R.N.P., Principal investigator, National Institute on Alcohol Abuse and Alcoholism (NIAAA)
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04714892
- Sponsor's protocol ID
- 10000261
- Other IDs
- 000261-AA
- Status last verified
- 16 Jul 2026
- First submitted
- 16 Jan 2021
- Last updated
- 13 Oct 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: We will share as stated in sharing plan of the protocol with proper MTAs in place.
Study at a glance
From the registry record, last updated by the sponsor on 13 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Mechanisms Underlying Individual Variations of Taste and Smell in Obesity
- ClinicalTrials.gov ID
- NCT04714892
- Acronym / sponsor ID
- 10000261
- Conditions
- Obesity
- Keywords
- chemosensation, Olfaction, Diet, obese, Perception, Natural History
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 350 participants (estimated)
- Lead sponsor
- National Institute on Alcohol Abuse and Alcoholism (NIAAA)US National Institutes of Health
- Study start
- 11 May 2022 (actual)
- Primary completion
- 30 Dec 2026 (estimated)
- Study completion
- 31 Dec 2026 (estimated)
- First posted
- 20 Jan 2021 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Background:
Changes to the sense of taste or smell can change eating behavior. This may contribute to obesity. Researchers want to see how taste and smell perceptions that affect food choices may differ between people with obesity and without obesity.
Objective:
To understand the role that senses of taste and smell play in food intake.
Eligibility:
Adults ages 18-65 with obesity and without obesity
Design:
Participants will be screened with a medical history and physical exam. They will have a neurological and sensory exam. They will give blood and urine samples. They will be checked for previous SARS-CoV-2 infection. They will complete questionnaires about their eating habits, alcohol use, and smoking history.
Participants will have 2 study visits.
Participants will give stool, urine, blood, hair, nasal, and saliva samples. These samples will be used for gene testing.
Participants will have their weight, height, and hip and waist circumference measured. They will have an imaging scan that measures body composition.
Participants will complete questionnaires about their health, eating habits, and food preferences.
Participants will have taste tests and smell tests. They will have sensory tests to assess their response to stimuli.
Participants will have a dietary assessment. They will complete a food diary and a diet history questionnaire.
Participants will get a meal to eat. Data will be collected about their experience.
Participants will complete a sleep diary and wear a watch to measure their activity....
Detailed description
Study Description:
This study involves comparison of taste and smell measures between obese and non-obese individuals. Taste and smell perceptions will be assessed in terms of their influence in food intake and food choices. We hypothesize that obesity negatively affects taste and smell perception thus affecting eating behavior.
Objectives:
Obesity is a major public health concern in America. An unhealthy diet is a recognized risk factor for the development of obesity. Public health efforts to modify eating behaviors have had limited success. Not only does an unhealthy diet contribute to obesity, but it can also lead to changes in gut microbiota that likely result in inflammation and changes in transcriptomic activity. Taste and smell perceptions, which can influence food choices and food consumption, may differ between obese and non-obese individuals. Currently, little is known about the underlying mechanisms causing variations in taste and smell systems in individuals with obesity, which limits the interventions currently available to address this critical issue. Findings from this study can be used to design more effective interventions for the prevention and treatment of obesity, to identify targets and strategies for countermeasures to prevent or improve obesity and its comorbidities, and to suggest ways to enhance dietary interventions. Moreover, findings will foster new lines of investigation for reducing risk of diet related conditions and for developing novel behavioral and pharmacological avenues of treatment and prevention. The proposed research is aligned with the overall mission of the National Institutes of Health to promote health and disease prevention. The findings from this study will ultimately lead to the development of personalized interventions for individuals with obesity and concurrent taste and smell alterations. Lastly, approaches included in this proposal are innovative and highly applicable to other complex health phenomena in which biological variations in inflammation and taste and smell perception impact an individual s health.
Endpoints:
Primary Endpoint: The primary dependent measures for this study are taste and olfaction measures.
Secondary Endpoints: Secondary measures include inflammatory markers, exosomes, microbiota, gene expression, DNA methylation, biological measures and personal factors.
Study design
- Observational model
- Case-control
- Time perspective
- Cross-sectional
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Healthy control | – | –BMI of 18.5-29.9 kg/m^2 |
| Obese | – | –BMI of 30-39.9 kg/m^2 |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
- Study population
- Participants will be recruited from the Washington DC metropolitan area and vicinity.
Key inclusion criteria (6 listed)
- In order to be eligible to participate in this study, an individual must meet all of the following criteria:
- Males and females between 18 to 65 years of age. Due to documented knowledge that taste and smell changes with age, we will limit the cohort within this age range.
- BMI between 18.5 and 29.9 kg/m^2 for healthy controls or between 30 and 39.9 kg/m^2 for obese subjects at screening
- Fasted plasma glucose levels between 68-126 mg/dl or per Clinical Center ranges, and hemoglobin A1C<6.5%
- Able to provide his/her own consent
Key exclusion criteria (19 listed)
- An individual who meets any of the following criteria will be excluded from participation in this study:
- Because type-2 diabetic subjects have blunted taste responses, subjects with diagnosis of type II diabetes will be excluded.
- Hypoglycemic drug intake.
- Weight change of more than 15 pounds in the 6 months prior to screening
- Positive pregnancy test, currently pregnant or breastfeeding.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Measures of taste and smell, and eating behavior
Time frame: At enrollment
Compare individuals with obesity to healthy controls in measures of taste and smell and eating behaviors.
4 secondary outcomes
Inflammatory markers, exosome and microbiota
Time frame: At enrollment
Gene expression, DNA methylation, taste and smell measures
Time frame: At enrollment
Biological measures, personal factors, taste and smell measures
Time frame: At enrollment
Severity of neuropsychological sysmptoms such as fatigue, anxiety, depression, sleep; perceived stress, pain and QoL
Time frame: At enrollment
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 13 Oct 2026.
- NIH Clinical Center Detailed Web PageLink provided by the sponsor.
- Individual participant dataSharing planned: Yes. We will share as stated in sharing plan of the protocol with proper MTAs in place.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Paule V Joseph, C.R.N.P. contact
Paule V Joseph, C.R.N.P. principal investigator
National Institute on Alcohol Abuse and Alcoholism (NIAAA)
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Obesity, run by National Institute on Alcohol Abuse and Alcoholism (NIAAA) at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 19 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 13 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Nada M Saleh ((301) 496-3799, nada.saleh@nih.gov), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Measures of taste and smell, and eating behavior (time frame: At enrollment). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 13 Oct 2026.