Are they indoor kitties like mine? If so, try growing 'Cat Grass' in pots on your windowsills. They love it and it's very easy to grow. It is very good for their digestion and distracts them from eating your house-plants.
You can buy the seeds almost anywhere that sells seeds for the garden.
Good luck!
And do not get Diffenbachia plants. Most cats will chew at any plant and will probably ingest the axalates which will burn their mouth, throat and gullet. Diffenbachia is as dangerous as rhubarb leafs.
Hi. I had a cat who also liked to eat my plant and pooin the pots! My neighbour told me that cats HATE pepper. So we put a small amount around the edge of the pot, and once she knew it was there wouldn't go by them. After about a week she never bothered with the plants again. Hope this helps.