The aim of this study was to evaluate the feasibility and the nutritional and depurative adequacy of the integrated diet dialysis program. The integrated diet dialysis program consists of a low-protein diet (0.4 g/kg ideal body weight/d), supplemented with essential amino acids or a mixture of essential amino acids and chetoanalogues, and once-weekly hemodialysis, tailored to maintain predialytic blood urea nitrogen levels lower than 90 mg/dL. Sixty-nine of 84 recruited patients with a mean age of 62.9 +/- (SD) 11.1 years and a baseline glomerular filtration rate of 2.54 +/- 0.94 mL/min entered the experimental phase; 15 dropped out, eight because of poor diet compliance. At 12-month follow-up, patient and technique survival were, respectively, 89% and 56%. The laboratory, anthropometric, and instrumental parameters of 28 patients with a follow-up of more than 12 months were also evaluated using repeated measures ANOVA. Mean predialytic blood urea nitrogen values were not significantly different (82 +/- 21 mg/dL v 93 +/- 26 mg/dL at baseline and after 12-month follow-up, respectively); total weekly KT/V from residual renal function plus dialysis (1.64 +/- 0.32 v 1.70 +/- 0.29; P = NS) and dialytic index according to Babb and Scribner (1.35 +/- 0.31 v 1.21 +/- 0.33) were stable. No problems were found as far as acid-base, calcium phosphate, water-electrolyte metabolism and blood pressure control are concerned. Body weight, fat free mass, fat, plasma proteins, albumin, and C3 and C4 complement factors were stable. Creatinine production (sum of metabolized plus excreted creatinine) decreased (14.3 +/- 3.2 mg/kg/d v 13.4 +/- 2.6 mg/kg/d; P < 0.05). Transferrin decreased but not significantly (221 +/- 46 mg/dL v 204 +/- 42 mg/dL; P < 0.09). Distal motor conduction velocity from the posterior tibial nerve did not improve during the study (37.8 +/- 4.9 m/s v 36.4 +/- 4.9 m/s), while distal motor conduction velocity from the median nerve worsened (50.8 +/- 4.3 m/s v 46.3 +/- 6.3 m/s; P < 0.05). In conclusion, even though the integrated diet dialysis program may be very important in the psychologically delicate phase between the conservative and the classical three-times-a-week hemodialysis programs, and may also solve some economic and dialytically related organizational problems, it arouses some concern as far as compliance and long-term nutritional and depurative adequacy are concerned. It should therefore be limited to highly motivated patients in centers with well-trained staff or where dialysis facilities are lacking.