Maybe change their diet to a light diet of white fish/chicken for now as Iams and Whiskas though great foods-don't suit every cat as they are both very rich and can be too rich for some cats or it can be that they're piggin' out so much and so fast at meal times that this is why they throw up after each meal. If you don't already try feeding them at separate ends of the room or in different rooms and see how they go coz you don't always hear whats being whispered at the food bowl and this could be making either or both anxious when they're eating and thats why they're rushing food down as fast as possible and then they're vomiting. Good luck Alphapets and do let us know how you and they get on