By changing to a mostly vegan/vegetarian diet I may have stopped CKD progression. Having read several books on CKD, I was most motivated by one called "Stopping Kidney Disease" by Lee Hull. I have no affiliation with this author. His research led to a suggested low protein vegetarian/vegan diet before it was recently adopted by the NKF.
As a CKD (in my case stage 3b), excess protein is a problem. Most people in the US get excess protein that impaired kidneys cannot process. This creates wastes in the bloodstream. The type of protein makes a huge difference with red meat being the worst. By giving up all meats (including beef, poultry, pork and lamb) and giving up eggs, dairy and fried foods, I have improved my kidney function. I still eat fish and whole grain cereals with almond milk. My protein comes from fish, beans and rice, legumes and vegetables. My eGFR has improved from about 34 to 50 which means I now have about 50% kidney function. My BUN has vastly improved as well as Creatinine. Awesome!
All this was accomplished in about 3 months of hard work with the guidance of a skilled dietician, I have also cut my salt and sugar intake as much as possible. No alcohol or sodas. Ultimately, you must commit to making changes yourself and resist temptations to "cheat" on your new lifetime diet because once you start cheating it leads to a breakdown. Only 10-15% of people who try this succeed. I will be one of them.
Diabetics have special needs and cannot eat rice, pasta and potatoes as I do, but veggies and fruits benefit most people and the American diet is basically unhealthy with excess salt and sugar and saturated fats. Eating healthy is expensive, but organic foods eliminate pesticides from items like strawberries and celery. My experience is that fructose and stevia are better processed and far less harmful than sugar or corn syrup.
Quality of life is more important than longevity for me and I will do all I can to avoid dialysis.
So he was never impressed with any knowledge I may have, cause I didn't have any! I'm 68 and I'm sure I've had this for years and years before I was accidentally diagnosed. But back then, you didn't want the diagnosis cause if you ever changed jobs, there was a chance you couldn't get insurance. So us PKD people were in a catch 22 situation back then. But even 2 years ago when I first heard of "CKD dietitian" my doc said, "Oh you get one of those once you're on dialysis", and that was the end of that discussion. I was not happy about that either. 
Resources: Understanding CKD Diet and Lab results
Nervous about having blood work done
How do you lose weight on a kidney friendly diet.
How can I gain weight on Kidney friendly diet?
