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....
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/m² for healthy controls or between 30 and 39.9 kg/m² 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
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.
Participants will be recruited from the Washington DC metropolitan area and vicinity.
Case-control
Cross-sectional
Not listed
Measures of taste and smell, and eating behavior
Compare individuals with obesity to healthy controls in measures of taste and smell and eating behaviors.
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.
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.
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
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
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