Good news. Diet and exercise actually worked for me!
Three months ago my kidneys were on a downward trend. My eGFR was 25, and my creatinine was 2.2. I asked my nephrologist if a plant-based diet could actually help. He gave me a guideline to eat mostly plant-based, interspersing animal protein (fish or chicken) three times per week.
About six week later my eGFR had risen to 29, and my creatinine lowered to 1.97.
Then I had an appointment with a nephrology nurse. He told me to exercise at least 30 minutes each and every day. I was already walking at least three miles about three times per week. I stepped up my exercise frequency and only missed two days in about a month.
Well, I had labs done Wednesday. My eGFR had risen to 31 (back to 3b territory), and my creatinine lowered again, to 1.86. Personally, I'm thrilled. I hope this can be an inspiration that hard work at this kidney thing can actually pay off.