Caloric requirements for spinal cord patients are not well understood. Energy expenditure was measured by indirect calorimetry and compared with predicted expenditure by manipulations of the Harris-Benedict (Long and Rutten), Quebbeman, and Spanier and Shizgal equations, using actual and ideal body weight: 45 measurements were made on 22 spinally injured patients, who were medically stable in their early rehabilitation phase of treatment, and included quadriplegics, paraplegics, and patients with Brown-Sequard syndrome. Other nutritional parameters were also followed. Equations based on normal patients consistently overestimated energy requirements of spinally injured patients.From the time of injury, spinally injured patients appear to have a reduction in their energy needs proportional to the amount of muscle which has been denervated. This decrease in caloric requirements continues throughout the rehabilitation and plateau phases. We have demonstrated that stable, rehabilitating spinally injured patients require 23.4 kcal/kg/day. As a group, quadriplegics required 22.7 kcal/kg/day, and paraplegics 27.9 kcal/kg/day. This represents only 45 to 90% of the recommended calories for maintenance as calculated by any of these recognized formulae, based on normal heights, weights, age, and sex, when using either current weight or ideal body weight.Spinally injured patients as a group are subjected to fluctuations in weight during treatment. Our own patients tended to become obese approximately 12 months after spinal cord injury on uncontrolled diets. All patients underwent an initial weight loss which was greater in the quadriplegics as a group, compared with paraplegics. On uncontrolled diets, our patients gained an average of 1.7 kg/wk and this was also greater in the quadriplegic group.