United States National Health and Nutrition Examination Survey 2011-2012

The National Health and Nutrition Examination Survey (NHANES) is an ongoing research survey designed to measure the health and nutritional status of adults and children in the United States. The survey examines a nationally representative sample of about 13,000 persons selected from 30 study sites across the country. NHANES uses a combination of interviews, physical examinations, and laboratory tests to collect data; interviews include questions concerning demographics, diet, conditions, and health status information, while the examination component consists of medical, dental, and physiological measurements. Blood, urine, and other samples are collected for a variety of laboratory tests and are also saved for a national probability sample of genetic material.