A Physician Nutrition Specialist® (PNS) is a physician with training in nutrition who devotes a substantial career effort to nutrition and who can assume a leadership role in coordinating interdisciplinary clinical nutrition services and education in academic health centers, other medical centers, private practice, and other health care settings. PNSs generally have backgrounds in the specialties of internal medicine, pediatrics, family medicine, or general surgery, and sometimes in subspecialties such as adult or pediatric gastroenterology, endocrinology, critical care, nephrology, cardiology, or others. They have completed a period of defined nutrition training, in addition to categorical residency training, that includes mastery of a defined core of knowledge and completion of a period of mentored clinical nutrition experience, which may be obtained in a nutrition fellowship or as part of training in another subspecialty. They have satisfied all requirements of, and are certified by, the American Board of Physician Nutrition Specialists.