HOW IS LEAN BODY-MASS CONSERVED WITH THE VERY-LOW PROTEIN-DIET REGIMEN

Eight CRF patients (GFR = 18.8 +/- 2.7 ml/min) underwent a crossover c omparison of a very-low-protein diet (VLPD) providing 0.28 g protein a nd 35 kcal/kg/day, plus an isomolar mixture of ketoacids (KA) or essen tial amino acids (EAA). During each dietary period, a 5-day nitrogen b alance (B-N) was performed and whole-body protein turnover (WEPT) was measured during fasting and feeding using intravenous [1-C-13]leucine and intragastric [5,5,5-H-2(3)]leucine. Although the VLPD/KA regimen c ontained 15% less nitrogen, B-N was neutral and did not differ between the regimens, Similarly, rates of WEPT did not differ between the KA or EAA regimens, and neutral B-N was achieved by a marked suppression of amino acid oxidation and postprandial inhibition of protein degrada tion (PD), Participants were then discharged on the VLPD/KA regimen an d monitored as outpatients for greater than or equal to 1 year. Repeat B-N was neutral and rates of WEPT did not differ from base-line value s. Thus, the adaptive responses to dietary protein restriction are sut ained during long-term therapy.