Optimizing Nutrition to Counter Sarcopenia in Hepatocellular Carcinoma: A Narrative Review of Mechanisms, Clinical Consequences, and Supportive Therapeutic Options

Patients with hepatocellular carcinoma (HCC) often sit at the crossroads of malignancy and chronic liver disease, where impaired hepatic reserve, systemic inflammation, and treatment-related stress accelerate loss of skeletal muscle mass and function. In this narrative review, we synthesize current evidence on the two-way relationship between sarcopenia and HCC management across curative and palliative settings. We outline key biological pathways-altered energy substrate use, amino acid imbalance, hyperammonemia-related signaling, and inflammatory and hormonal perturbations-that promote progressive muscle wasting, and we summarize how sarcopenia influences tolerance, complications, and outcomes of surgery, locoregional therapies, and systemic agents. We then translate the literature into practical supportive-care principles, including adequate energy and protein delivery, optimized meal distribution (including late-evening snacks), and selected supplementation alongside hepatic rehabilitation/exercise. Potential adjuncts discussed include branched-chain amino acids, L-carnitine, vitamin D, zinc, and other micronutrients. Because the available data are heterogeneous and largely derived from observational cohorts or extrapolated from cirrhosis populations, HCC-specific randomized trials and standardized intervention protocols remain limited. Therefore, nutritional and exercise recommendations should be individualized according to tumor stage, hepatic function, comorbidities, and treatment goals, and viewed as supportive guidance that requires confirmation in well-designed prospective studies.