Total enteral nutrition support improves body composition of patients with active Crohn's disease

Previous studies using indirect calorimetry in Crohn's disease have suggested that with weight loss there is a proportionally greater decrease in body fat along with a spring of lean mass. This study analyzed body composition (compared with that of controls) by direct methods in a group of 30 patients with active Crohn's disease and further evaluated the effects of nutrition support on body composition.

Total body protein was assessed by neutron activation, fat was assessed by dual energy x-ray absorptiometry, water was assessed by bioelectric impedance analysis, and potassium was assessed by gamma-ray technique. These measurements were repeated in patients with Crohn's disease after 3 weeks of enteral nutrition by feeding tube that provided 35 nonprotein kcal/kg of ideal body weight.

Compared with age- and sex-matched controls, patients had lost (on average) 11.3 kg (16%) of body weight (p < .0005), including 5.1 kg (30%) of fat (p < .0005), 2.2 kg (19%) of protein (p < .025), 3.7 kg (10%) of water (p = NS), and 24.9 g (21%) of total body potassium (p < .01). After enteral feeding, body weight increased by 1.9 +/- 0.3 kg (p < .0005). Weight gain was accompanied by an increase in body protein (0.3 +/- 0.1 kg), fat (0.3 +/- 0.1 kg), and water (1.1 +/- 0.4 kg) (all p < .025), and by a nonsignificant increase in total body potassium. The weight gain of approximately 2 kg consisted of 65% water, 18% fat, and 18% protein, thus comprising a normal proportion of body composition.

Reduced body weight in patients with Crohn's disease compared with that in controls was due to less fat tissue. With modest nutritional repletion, proportionate gains in all body compartments are possible.