Low Protein Diet in CKD Patients at Risk of Malnutrition

Nutritional status will be evaluated through: * Malnutrition Inflammation Score (MIS), * Anthropometric measurements, * albumin, prealbumin, transferrin, * 24h urinary nitrogen, * bioimpedance analysis (BIA), * periodic 24h dietary diaries, * International Society of Renal Nutrition and Metabolism (ISRNM), Physical performance will be evaluated through: * Short Physical Performance Battery (SPPB) * Handgrip strength Inflammation assessment: * c-reactive protein (CRP) * Interleukine-6 (IL6) * whole blood Neutrophil/lymphocyte ratio Renal function assessment: * eGFR based on serum creatinine and cystatin C * average creatinine and urea clearance Uremic metabolic alteration: * serum urea * serum phosphate * serum FGF23 * parathormone (PTH), * plasma pH and bicarbonate Time points of evaluation Dietary compliance has been assessed by a trained nutritionist at months 1, 2, 3 and 6. Dietary consumption was estimated by using dietary diaries and normalized catabolic protein rate (nPCR) measurement at baseline, 3 and at 6 months. Nutritional status and physical performance have been evaluated monthly for the first three months and then at 6 months.