Kidney disease is a problem that afflicts millions of individuals, and it interferes with many aspects of everyday life, not just your medical life. The foods that you eat are one of the big ways that it interferes with the life of your family, as you are to avoid foods that are encouraged for many other people. As you sound like you are dedicated to helping preserve your kidney function to the greatest degree, you should speak to your nephrologist
about which diets will be best for you.
While I am not aware of foods that will help your kidney disease per se, there are restrictions that have been noted to have a moderate effect on preserving renal function. One of these is mild protein restriction. As this can be unhealthy for some people, it would be necessary to speak with your nephrologist about whether or not this would be of any benefit for you, as it is not a good solution for many people. The key to managing your renal function and minimizing the impact your disease has on your life will be in maintaining excellent communication with your physicians and agreeing on a course of therapy that is sustainable.