Since my Storm was blocked 2 times and then needed PU surgery, I can't afford to fool around with the food that I feed him. So far the Royal Canin Urinary S/O has been working and this helps prevent both the struvite crystals and the calicium oxalate crystals. I'm now feeding this to all of my cats because I have 4 males and it shouldn't hurt them. Now with Starr's issues I'm going to try the Natural Balance Venison & Green Pea Allergy Formula to see if this will help his diarrhea problems.

Since the Natural Balance worked before, I'd just stick with it and just feed your cats less of it to help control their weight. Good luck.