Glycemic control in the critically ill patient has remained a controversial issue over the last decade. Several large trials, with widely varying results, have generated significant interest in defining the optimal target for blood-glucose control necessary for improving care while minimizing morbidity. Nutritional support has evolved into an additional area of critical care where appropriate practices have been associated with improved patient outcomes. Carbohydrate provision can impact blood-glucose levels, and the relationship between nutrition and glucose levels has become more complex in the era of improved glycemic control. This review discusses the controversy surrounding intensive-insulin therapy in the intensive care unit and explores the relationship with nutritional support, both in the enteral and parenteral form. Achieving realistic goals in both carbohydrate provision and glycemic control may improve patient outcome, and are not mutually exclusive practices.