Nutrition in children with preterminal chronic renal failure. Myth or important therapeutic aid?

Nutrition has been believed to be an important therapeutic instrument in children with chronic renal failure (i) for improving growth, and (ii) for slowing down the deterioration of renal function. The therapeutic strategies for both targets may be conflicting, at least in part, since a high calorie intake is needed for optimal growth, whereas a low protein diet, which was believed to protect renal function, places patients at risk of low calorie intake. Dietary manipulations for optimal growth are mainly effective in infants with chronic renal failure. However, growth remains suboptimal even with an energy intake above 80% of RDA. Although a low protein diet is able to slow down the rate of deterioration in renal function in rodent studies, the results of prospective clinical studies were disappointing at least for an observation period up to three years. The conclusions out of meta-analyses of these clinical studies in adults are contradictory. The progression rate was not significantly influenced by protein restriction, whereas renal replacement therapy could be postponed. However, the latter seems to be the effect of weakening uremic symptoms during the phase of end-stage renal failure. According to our present knowledge it is not justified to prescribe special diets to children early in the course of chronic renal failure, but the composition of their nutrition should follow the general concept of an optimal mixed diet.