Parenteral nutrition and oral intake: effect of branched-chain amino acids.

The effect of peripheral parenteral nutrition (PPN) on voluntary food intake was examined in healthy male subjects. Each study (lasting 17 to 19 days) was divided into three phases: Ringer's lactate (RL); PPN administered as a combination of glucose, fat, and amino acids; and finally RL. During the middle phase, some of the subjects received a parenteral formula in which half of the amino acids had been replaced with the branched-chain amino acids (BCPPN). When PPN was infused, subjects reduced their food intake within 48 hours by approximately 80% of the infused calories (p less than 0.001) within 48 hours, whereas intake was reduced by less than 40% of the infused calories when BCPPN was infused. Use of branched-chain amino acid-enriched parenteral nutrition may minimize the reduction in food intake seen during intravenous nutrition, possibly hastening a return to normal eating.