My cat was diagnosed with early kidney disease and our Vet told us that she now has muscle wasting due to the lower protein diet that was originally prescribed. Low phosphorus diets are important. You have three that have varying phosphorus levels, why?
Mature Health ranges from 0.55% up to 0.65% because it contains chicken. The levels of phosphorus can vary in chicken so we use a range of possibilities. The Zero Mature at 0.50% has less chicken and the LID at Mature has no chicken. For a cat with kidney disease the LID mature would be your best choice because, it is low in P and it only uses a hydrolyzed protein source, which is much easier for a kidney compromised cat to digest.
Low protein was always thought to benefit a kidney disease cat. However new research has found that high protein is better for the cat as long as the protein source is from meat and is highly digestible. Older cats need higher levels of protein to maintain their muscle mass and overall general health.