Nutrition is an important aspect of care for any patient entering the hospital, but the patient admitted to the intensive care unit (ICU) is at an even higher risk for nutritional compromise. Nutrition affects all ages, from the neonate to the geriatric patient, and all patient populations. Evidence-based practice guidelines regarding appropriate nutritional support within the critical care setting are published. Yet, researchers continue to identify that despite published evidence, countless ICU patients continue to lack adequate and timely nutritional support on admission. Each of the authors in this issue promotes nutrition in their careers and individual practice areas, which brings knowledge from many different arenas throughout the nation. This issue discusses nutrition throughout the lifespan, special patient populations, implementation of guidelines, and how nutrition is being utilized as medical therapy.