Prior to Stage 5, my diet was pretty normal. I had a great nephrologist, who encouraged me to eat healthy and not go crazy trying to eliminate protein and salt, because that can cause a whole new set of problems. That being said, I reduced my salt by not eating fast food, or salty snacks (crackers, potato chips, etc). I ate protein at one meal but not all three. That was about it.
My diet changed as I went into Stage 5 kidney failure. The thought of eating meat, of any sort, became nauseating. I could eat some tuna, but only every once in a while. The thought of a salty french fry, was disgusting. The quantity of food I could digest was greatly reduced. I tended to just want toast or oatmeal in the morning; a low protein, high vitamin c smoothie in the afternoon; and honestly, just easy to digest starch at night- like toast, pasta, mashed potatoes- but if I overate, I got nauseous. For me, my body told me what it could handle, and I listened.
I'm sure Mayo has much better dietary advice than I do. The NEPRO sounds like a good idea.