The National Health and Nutrition Examination Surveys (NHANES) are a group of studies that measure the health and nutritional status of U.S. children and adults. It is conducted by the National Center for Health Statistics (NCHS), Centers for Disease Control and Prevention (CDC). NHANES is the only NCHS survey that gathers objective health measurements based on physical examinations. NHANES contributes to the mission of CDC and the Department of Health and Human Services (DHHS) by collecting standardized data that help shape policies and programs to promote health by preventing and controlling disease and disability. Also, NHANES helps NCHS fulfill its responsibility for producing vital and health statistics for the nation.