Providing nutrition and metabolic support to the CCI patient is based on the rational application of scientifically derived data and clinical experience with this unique population. Much of the data presented has been extrapolated from the critically ill ICU patients and the chronically ill hospitalized or nursing home patient, as there are limited data solely based on an experience with the CCI [table: see text] patient population. The key principles are: (1) primacy of protein provision and avoidance of overfeeding energy, (2) use of combined modality (enteral, parenteral, and oral) nutrition to meet needs as required, (3) use of adjunctive agents to promote nitrogen retention when needed, and (4) recognition of and adjustment for altered nutrient requirements (Table 3).