It's a :reddit-logo: link, but the vegan pets page has a log of good peer reviewed articles on how one would go about this and a big summary of studies on the subject. Scroll through this page and check out the studies cited. People heard cats were obligate carnivores and are always happy to jump on the "actually you're the animal abuser" train, but their is significant research saying it can be done if carefully monitored and it can even be healthier for the animals, reducing obesity and other diseases in some cases. Link to the resources here