For instance, in one study of patients with CKD, a very-low-protein diet containing 0.3 g protein/kg of body weight/day (< 500 mg/day of phosphate) led to a significant decrease in FGF23 levels [21]; however, submitting individuals with CKD to such a protein-restricted diet exposes them to a high risk of malnutrition [22]. The gene discussed is FGF23; the disease is chronic kidney disease.