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Patient Recruitment

Brain Dopamine Function in Human Obesity

Does Your Brain's Reward System Influence Your Weight?

a scale and dumbbells

Researchers at the National Institutes of Health (NIH) seek healthy volunteers to participate in a study investigating how dopamine affects body weight and eating behavior. Dopamine is a natural chemical in the brain that may influence eating and physical activity. Researchers want to measure the brain's dopamine activity and understand how it varies in people who have different amounts of body fat.

Study participants will:

  • Have a screening visit to include medical history, physical exam, blood and urine tests
  • Eat a special diet, provided by the study, for 5 days
  • Have a 5-day inpatient visit which will include blood and urine tests, body imaging (MRI and PET scans), and tests to measure metabolism
  • Track their daily weight and physical activity for 12 months following the inpatient stay
  • Have a 1-day follow-up visit

You may be eligible if you:

  • Are 18-45 years old and a non-smoker
  • Have a BMI of at least 18.5 kg/m2 (calculate your BMI at
  • Are generally healthy and have not gained or lost weight recently
  • Have normal blood pressure and not taking blood pressure medications
  • Are not using illegal drugs (based on urine drug screen)
  • Are not following a special diet
  • Do not have metal implants
  • Are able to visit the Clinical Center for 5 consecutive days to pick up food and then have a 5-day inpatient stay

Compensation is provided.

Location: The NIH Clinical Center, America's Research Hospital, is located in Bethesda, MD on the Metro red line (Medical Center Stop).

For more information:
NIH Clinical Center Office of Patient Recruitment
877-444-6670 (refer to NIH study 18-DK-0132)
866-411-1010 TTY for the deaf and hard of hearing
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Or go online:

Department of Health and Human Services
National Institutes of Health Clinical Center (CC)
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

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This page last updated on 10/22/2021

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