Abstract The combination of poor dietary intake and increased healthcare needs predisposes COVID-19 patients to malnutrition and sarcopenia. The scope of this narrative review is tο present epidemiology and etiology of malnutrition and sarcopenia in COVID-19 patients, their consequences as well as the content and delivery mode of optimum nutritional services for malnourished/sarcopenic COVID-19 patients in the rehabilitation setting. This narrative review also summarizes nutritional recommendations, consensus statements and treatment pathways developed by scientific societies for COVID-19 patients. COVID-19 patients are prone to malnutrition and sarcopenia due to inactivity, comorbidities, cytokine response, nutritional deficiencies, anosmia, loss of taste, anorexia and treatment with dexamethasone. Thus, all COVID-19 patients, including those who are overweight or obese, should be regularly screened for malnutrition and sarcopenia at admission to the rehabilitation setting, using a validated tool to identify those with (or at risk of) malnutrition. As a consequence of malnutrition and sarcopenia, COVID-19 patients demonstrate diminished immune potential, lower respiratory function, swallowing dysfunction, and low resilience to metabolic stress. COVID-19 patients have increased energy (27-30 kcal/day) and protein needs (1-1.5 g/kg body weight/day). Personalized nutritional education and counseling, food fortification with energy dense and/or protein rich whole foods or with powdered supplements and use of high protein, energy dense oral nutritional supplements are recommended.