@celia16 You will find lots of good information here on this thread of discussion. We have found, as kidney disease patients, that diet plays a critical role in daily maintenance of our situation.

One of the first things is to understand what the cause of your dad's kidney disease may be. Uncontrolled high blood pressure or diabetes can be the two main causes. Other causes can be long term medication side effects, lifestyle, or hereditary issues. It's important the root cause also be addressed.

The basic renal diet focuses on limited or no over-processed foods, monitoring sodium/phosphorous/potassium/calcium contents in food. Good hydration, moderate exercise, and stress reduction are also good goals!
Ginger