Endoscopic injection sclerotherapy (EIS) is conducted to treat esophageal varices associated with liver cirrhosis. Cirrhotic patients have protein energy malnutrition (PEM), and their malnutrition is aggravated during EIS due to dietary restrictions. The aim of this study was to evaluate the dietetic benefits of oral branched chain amino acid-rich nutrient (BCAA-rich nutrient) administered during EIS. Cirrhotic patients admitted for prophylactic EIS were divided into three groups: Group A given a general liquid nutrient in two divided doses, Group B given a BCAA-rich nutrient in two divided doses, and Group C given the BCAA-rich nutrient in four divided doses. The nutritional state was evaluated based on physical examinations, biochemical parameters, and indirect calorimetry. A total of 29 patients were enrolled. Blood biochemical examinations showed a significant increase in the Fischer's ratio in Groups B and C. Group B showed significant decreases in resting energy expenditure/basal metabolic rate, while Group C showed a significant rise in non-protein respiratory quotient. The oxidation rate of carbohydrate significantly increased and that of fat significantly decreased in Group C. Administration of the BCAA-rich nutrient is considered to be useful in improving abnormalities of energy metabolism during EIS.