We measured resting metabolic rate (RMR) in 12 persons (aged 10 to 30 years) with severe impairment of the central nervous system requiring gastrostomy feedings, and compared our findings with the RMR predicted from standardized equations. The RMR was 70.6% +/- 15.7% of that predicted from the Mayo Clinic nomogram, 63.7% +/- 18% of that predicted from the Food and Agriculture Organization/World Health Organization/United Nations University equation, and 75.4% +/- 17.3% of that predicted from the Robertson and Reid equation. Energy intake was 756 +/- 225 kcal/day and RMR was 708 +/- 231 kcal/day; RMR adjusted for changes in body energy stores was 729 +/- 231 kcal/day. No significant differences were found between energy intake and RMR, or between energy intake and the sum of RMR and changes in body energy stores. These findings demonstrate that standardized equations overestimate energy needs of individuals with severe CNS impairment. Measures of energy intake adjusted for weight changes represent a valid method to determine energy requirements in a group of individuals with severe CNS impairment. Length was found to be significantly correlated with RMR (r = 0.79; p < 0.01). When the regression equation was tested on another group of subjects from the same residential facility, the equation predicted energy needs reasonably well for those individuals with similar energy intakes but not for all patients with CNS disorders.