The basal energy expenditure (BEE) calculated from the Harris-Benedict equation was compared with the resting energy expenditure (REE) measured by indirect calorimetry in 12 consecutive hospitalized patients with inflammatory bowel disease. The BEE proved to be equivalent to the REE in the prediction of daily caloric requirements. Patients weighing less than 90% of their ideal body weight had significantly increased energy requirements on a per-kilogram-weight basis as compared with those weighing more than 90% of their ideal body weight. Daily caloric requirements based on 1.75 X BEE would provide 45 kcal/kg/24 hr, which is consistent with reported values necessary for anabolism.