Total energy expenditure in patients with Crohn's disease: measurement by the combined body scan technique.

A combined body scan technique for measuring total energy expenditure (TEE) from energy intake and changes in energy stores is presented. The TEE of 13 patients with Crohn's disease who required nutrition support over a 14-day period was measured. They had a mean TEE of 33 kcal/kg per day. The components of the TEE in these 13 patients were also measured. Seventy percent of the TEE was made up by resting metabolic expenditure, 10% by diet-induced thermogenesis, and the remaining 20% by activity energy expenditure. These patients had a mean activity energy expenditure of 369 kcal/day. The diet-induced thermogenesis was a mean 12.6% increase on the resting metabolic expenditure. Each percent increase was caused by a mean of 210 kcal of energy in either the intravenous nutrition or the enteral nutrition. There was no difference in diet-induced thermogenesis between those having enteral nutrition and those receiving intravenous nutrition. Decreased activity was significantly correlated with increased activity of the disease (r = .7, p < .01). This confirms the belief that patients with Crohn's disease require no more energy (ie, 33 kcal/kg per day) than other patients. If the resting metabolic expenditure is increased through illness, then the activity energy expenditure decreases. The combined in vivo neutron activation-dual energy x-ray absorptiometry technique has allowed for the first time measurements in ward patients with Crohn's disease. The measurements confirm that TEE is not raised and that 30 to 35 kcal/kg per day is sufficient to achieve energy balance in such patients.