Dietary Modulation of Urinary MCP-1 in ADPKD

Inclusion Criteria: 1. Age ≥18 2. Diagnosis of ADPKD based on established clinical or genetic criteria (PKD 1/PKD2) 3. Estimated glomerular filtration rate (eGFR) between 45 and 90 mL/min/1.73 m² 4. Mayo Imaging Classification class 1C-1E based on MRI-derived height-adjusted total kidney volume. 5. Stable kidney function, defined as no acute kidney injury and no decline in eGFR \>20% within the preceding 3 months 6. Stable antihypertensive and chronic medications for at least 4 weeks prior to enrollment 7. Ability and willingness to adhere to the prescribed dietary intervention 8. Ability to provide written informed consent Exclusion Criteria: 1. eGFR \<45 mL/min/1.73 m² or requirement for dialysis 2. History of kidney transplantation 3. Significant albuminuria, defined as urine albumin to creatinine ratio (UACR) \>300 mg/g 4. Poorly controlled or unstable diabetes mellitus (e.g., HbA1c \>8% or clinically significant glycemic variability or frequent hypoglycemia) 5. Use of Tolvaptan at the time of screening or within the study period 6. Current adherence to a ketogenic or carbohydrate restricted diet 7. Unintentional weight loss \>5% within the preceding 3 months 8. Active infection, inflammatory disease, or malignancy that may influence inflammatory markers 9. Current use of systemic corticosteroids or immunosuppressive therapy 10. Active or symptomatic nephrolithiasis 11. Serum bicarbonate \<20 mmol/L 12. Pregnancy or breastfeeding 13. Known eating disorder or condition limiting adherence to dietary interventions 14. Participation in another interventional study within the previous 3 months 15. Any condition that, in the opinion of the investigators, would interfere with study participation or interpretation of results