I usually leave some food down for them to graze on. I am now picking up ALL food when they walk away. Sunny spent the day at the vets yesterday due to crystals so he is now on prescription food and can't have the other food. He gets fed in a spare bedroom while the others get food in the dining room. I am going to have to change the bedtime routine too. They all get treats at bedtime, but he can't have them. My cats have such a set routine they are not going to like this. Last night I kept him apart from the rest of the cats to make sure he used the box overnight but I think tonight he will be back in the general population. This is my Sunny (Posiepurrs Sunflower) It was difficult to come up with a registered name that went with his call name Sunny so he got stuck with Sunflower! 
I'm sure the other cat's will get used to the new routine once they release your not going to give in to them. And please give Sunny a cuddle from me instead of a treat. Glad he's home where he belongs.
