We investigated the nutritional state and pathophysiologic mechanisms involved in the malabsorption of 27 patients with total gastrectomy and esophagojejunostomy reconstruction without reservoir; they were first evaluated after a median period of 9 months after surgery and were not receiving either nutritional or pharmacologic support. Mean postoperative weight loss was −13.7 ± 1.59%; mean daily caloric intake was 31.7 ± 2.41 kcal/kg/day, with 70% of subjects ingesting <30 kcal/kg; P/kg was 1.2 ± 0.09, with 21% of patients ingesting <1 g P/kg/day; mean ratio of nonprotein energy to 1 g nitrogen intake was 142 ± 8.74:1, with only 24% of patients attaining a ratio >150:1; and mean fat malabsorption was 37.4 ± 4.6%. Hemoglobin (Hb), serum albumin, prealbumin iron, and folate were more often abnormal in the early postoperative period, whereas transferrin and vitamin B12 concentrations deteriorated later. α1-Antitrypsin clearance was abnormal in almost all patients (indicating an intestinal protein loss), and the pancreolauryl test was abnormal in 60%. Neither morphological nor absorptive alterations of the small bowel nor an abnormal transit time or bacterial overgrowth was found. We conclude that inadequate caloric intake appears to be the main cause for malnutrition after total gastrectomy, but that caloric losses caused by steatorrhea and enteric protein leakage must be subtracted from intake, thus decreasing the amount of available calories.