Protein restriction in the pre-end-stage renal disease (ESRD) patient: who, when, how, and the effect on subsequent ESRD outcome.

The protein and energy requirements of patients with chronic renal failure are similar to those of healthy subjects, and evidence indicates that both nephrotic and nonnephrotic chronic renal failure patients can activate normal homeostatic responses allowing them to maintain lean body mass when dietary protein intake is restricted. The benefits of low protein (and phosphorus) diets include the amelioration of uremic symptoms and some of its metabolic complications, and possibly slowing the rate of progression of renal failure. Moreover, there is no evidence that the use of low protein diets (LPD) in the predialysis period results in worse outcomes once dialysis is initiated. When LPD are prescribed, patients should be monitored to assess dietary compliance and to ensure nutritional adequacy. Recent evidence that nutritional indices of patients with progressive chronic renal failure declines when they consume unrestricted diets should not be interpreted as justification against the use of LPD. Rather, it is a compelling argument to institute dietary therapy to minimize complications of renal failure while maintaining nutritional status. Finally, the use of LPD is compatible with "timely" initiation of dialysis in accordance with recommended guidelines.