I am a multiple cats and dogs household.

what my wife and I do is that we have trained each one. ....

they each have their own water and food dishes. they each have their own spot in the same room where their respective dishes are.

We do .......not......... free feed (set down food and leave it there for them to snack on all day and night)

all cats are on canned (other wise called Wet food), Yes it is more expensive but better for when cats are on special diets. the canned foods come in a variety of flavors and sized cans and a variety of health needs and ages of the cats.

the correct amount of cat food to feed cats is one ounce of cat food for desired weight you want the cat to be. (example if the vet says this cat needs to be 10 pounds, this cat gets 10 ounces of cat food a day)

on canned our cats have less digestive and urinary problems and also their weights maintain at a healthy level set by the vet.

we do not feed our cats every time we eat, nor do we feed them snacks and handfuls of treats when ever we think they are hungry. they are on a feeding schedule and have been taught not to beg, barrow or steal, cause a rucckus when we are eating, or snacking.

we also make sure our cats have plenty of exercise in way of toys, boxes to explore and places to climb and claw. cats are preditory animals, they do not spend their day snacking and begging like humans do.

they sleep, they play and rely on humans to keep them healthy. if they were out in the wild they would be exercising while they play and stalk their prey,

our cats have lots of toys, shoe strings, balls, places to climb and explore, sometimes we even leave closet doors and cupboards open just a crack, just enough to peak their curiosity and encourage their instinctual stalking/ preying play about an hour before we feed them, just like if they were out in the wild and their bodies tell them its time to start looking for food.

if you are consistent your cats will learn which food and water dishes and spot in the room is theirs and when its time to play and exercise, time to sleep and time to eat. and they will eat only their own foods. but you have to be consistent.