Nutritional abnormalities almost uniformly accompany the metabolic disturbances of severe chronic liver disease and may adversely affect patient well-being and survival, especially surrounding liver transplantation surgery. The exact metabolic alterations responsible for malnutrition and its consequences in these patients have been debated and are a focus of this review. Disturbances in energy production and utilization, as well as macro- and micronutrient metabolism have been appreciated but are not always easily identified or quantifiable. Interestingly, the manifestations of poor nutritional status can vary substantially between patients, even in those having the same etiology and severity of illness. Proper assessment of patients with liver disease for malnutrition carries its own challenges, but some of the more easily applied techniques, such as anthropometry, can be comparable in accuracy to more sophisticated measuring tools. Gaining an appreciation and understanding of how nutritional disturbances develop and can contribute to morbidity and mortality will help combat inappropriate nutritional losses in this specialized group of patients. In many instances, simple adjustments in diet can offset losses and stabilize or improve the patient's nutritional status.