The portacaval anastomosis (PCA) rat model and human cirrhosis have many metabolic and nutritional abnormalities in common, such as growth retardation, hepatic and gonadal atrophy, and hyperammonemia. The severity of these abnormalities is variable and may be related to a number of factors, including portal pressure, portosystemic shunting, dietary intake, and how efficiently food is used. Therefore, this rat model was used to study these variables with the intent of gaining insights for improving the management of portal hypertension and malnutrition in human cirrhosis. A nonsuture end-to-side PCA (N = 100) or sham surgery (N = 71) was performed in 100 male rats. Four weeks after surgery, body and organ weights, food intake, serum ammonia, and serum amino acids were measured at death. In a subgroup of rats, (sham 7; PCA 34) portal venous pressure, degree of portosystemic shunting, and organ and body weights were obtained at death. Growth, liver weight, and testes weight were decreased, ammonia levels were higher, and the ratios of branched chain to aromatic amino acid (BCAA/AAA) were lower in the PCA group compared to the sham animals (P < 0.05). Since spleen weights correlated with portal pressure (P = 0.01), the PCA animals were then divided into those with preserved and those with low portal pressures based on spleen weight. The PCA group with preserved portal pressure had better growth, larger livers and testes, lower serum ammonia, and higher BCAA/AAA levels than the PCA group with low portal pressure; improvements associated with normal amounts of food intake and better food efficiency than the low pressure animals (P < 0.05 or better). Sham animals had no portosystemic shunting, while 100% shunting occurred in both PCA groups regardless of the portal pressure. In conclusion, preservation of portal pressure after portacaval anastomosis provides metabolic and nutritional benefits, which are independent of portosystemic shunting and associated with normal dietary intake and better preserved food efficiency.