Hi, I was also told to just watch the hydration part. When I saw a Renal Nutritionist/Dietician though I learned so very much more. I am at stage 3B and it bounces in eGFR numbers with every test. I researched the reason for this and learned that we are supposed to abstain from eating protein for at least the night before throughout the test as that messes with the numbers. My Nutritionist also has me reading the book called, The Complete 4-in-1 Kidney Disease Diet and Food List Guide for CKD Stages 3-4. It's written by Janeth Kingston, BSN, RN and sells on Amazon. I highly recommend this book. Damage from kidneys is never undone so like a previous comment says we can only work on stopping damage that will happen in the future and delay it as long as possible. Do everything in your power to save your kidneys. Have a great day and update us with what you learn and do.