Alternatives to total parenteral nutrition (TPN) can play an invaluable role in the support of the critically ill patient. However, the efficacy of this depends on: (1) early nutritional assessment; (2) sequential nutritional assessment as dictated by the clinical condition of the patient; (3) careful estimation of requirements based on calculated energy expenditure and use of the “stress-index”; (4) early use of enteral feedings in combination with peripheral and central intravenous routes, especially with the use of “feeding modules” to provide patient's specific concentrated diet; (5) use of intravenous fat as an isotonic supplement to dextrose in the presence of carbohydrate intolerance; (6) avoid overfeeding as rigorously as underfeeding; (7) continued clinical trials to determine optimal nutritional/metabolic support of the critically ill