Nutritional therapy has a leading role in the conservative treatment of chronic kidney disease (CKD). In the context of CKD, nutritional therapy means designing diets to reduce the patient's intake of proteins, phosphorus and sodium, while preserving adequate energy intake. Nutritional therapy may require also supplementation with calcium carbonate, iron, or essential amino acids and keto acids. Different nutritional strategies can be devised according to the protein needs of CKD patients: diets with controlled protein intake (protein RDA: 0.8 g/kg/day); low-protein and low-phosphorus diets (protein: 0.6 g/kg/day, phosphorus: 500-700 mg/day); very low-protein and low-phosphorus diets (protein: 0.3 g/kg/day, phosphorus: 300-400 mg/day). Much of the protein intake should be of high biological value (e.g., 0.4 g/kg/day of 0.6 g/kg/day or supplementation with essential amino acids and keto acids is needed). The sodium chloride content of low-protein and very low-protein diets should be kept between 2 and 5 g/day according to individual needs, and the energy intake should be kept at 30 to 35 kcal/kg/day.