Ken Berry, MD, a family physician, discusses polycystic kidney disease (PKD), the most common inherited kidney disease. PKD is characterized by enlarging cysts in the kidney that can lead to decreased kidney function and end-stage kidney diseases. Symptoms include decreased kidney function, urinary tract infections, kidney stones, blood in urine, high blood pressure, and abdominal or flank pain. Research in animal models has shown that being in ketosis, achieved through a ketogenic diet and intermittent fasting, can slow down the progression of PKD and improve kidney function. A recent human study confirmed these findings, showing that a ketogenic diet can shrink the size of polycystic kidneys and cysts and improve kidney function. Dr Berry recommends a whole food, ketogenic diet and some degree of intermittent fasting for those with PKD or at risk of developing it. He also debunks common misconceptions about protein, salt, water, caffeine, and alcohol intake for PKD patients.