About a year ago she ended up in the hospital from non-stop vomiting. After a bunch of tests the best we could come up with was a food allergy (she's always had a scarf and barf tendency even before this episode), so we moved her to a 100% hydrolyzed protein diet. We didn't get around to trying food challenges to get her off the hydrolyzed protein until after her diagnosis.
After the diagnosis, I tried a limited ingredient food, but ended up getting more vomiting than I was comfortable with. So, next step was single ingredient foods to really take it one step at a time. I settled on Tiki Cats luau chicken, which is nice because it's just chicken plus vitamins/minerals. But, it's 0% carbs. I've been gradually shifting more and more of her diet to the Tiki Cats, and we're now down to 5% ME from carbs. I've been a bit paranoid about going to zero carbs because I'm away from home for 10-12 hours at a time three days a week. But, I'm continuing to inch it down.
I have a hunch that peas were the issue, so I may try a different food that naturally has small amount of carbs from a different source, possibly in combination with the Tiki Cats to keep the overall percentage low. But, the terrible ingredients aside, the nice thing about the z/d is that I have a year track record of Pumpkin tolerating it very well. I really don't want a diabetic cat to get into another non-stop vomiting episode.