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....