cats with eating disorders?

It has been a struggle the past few days in this house between Us and the cats. Porter is trying to get fatty-mc-fat-pants on us and eat Charlie's food and Charlie decided he wants to eat nearly 1/4 of what he should be eating.
Before Charlie came along Porter has never had any reason to worry about his next meal. He gets a breakfast and then a dinner when I get home. We recently upgraded one of his meals to a more cat-friendly wet food which he loves. With two food bowls out now he is trying to keep Charlie's head out of his bowl and he also tries to sneak some extra food when we are not looking. There is some competition eating going on these days and it is not good for him. I don't want a fatty cat!
And then there is Charlie who is deciding he is not hungry. He should be eating the equivalent of 4 "servings" a day (where Porter gets only 2). He might be getting one whole serving... if I sit there with him and coax him into eating. How do you coax a cat? Well, for Charlie it involves me feeding him on the bathroom counter with the door shut so he can focus on the task at hand- dinner! I have to sit there next to him literally touching him the whole time. He will take a few bites then want to nuzzle me. I don't know where this is coming from!? He was doing so well with eating all of his food just a few days ago.
We are going on vacation soon and this new habit is a big problem. We can't have the pet sitter (will blog about the pet sitting services another day- they are AMAZING!) there all day to keep them eating the way they should be. They will be there twice a day while we are gone- once for breakfast and once for dinner. During each 30 minute visit they will feed the cats, brush them, change the litter box and play with them. I can't have the food ritual take up all of their time. So what to do?! Unfortunately I think they will have to stay on dry food while we are gone because it is the one way I can be sure Porter won't overeat. He is only mildly thrilled with dry food so once he has had enough I can be sure he won't be snacking on Charlie's. I just hope Charlie eats enough. Surely he will eat if he is hungry- right?!?
I wish I could have gotten Charlie on video trying to fight Mark for a piece of chicken the other day. We do NOT give our cats table food and especially Charlie who is so young would not have a history with table food but sure enough we were having dinner at the table when Charlie decided to join us. He jumped on the table and was going manic trying to get past Mark's hands to eat that chicken. His whole body was shaking and he was crying and Mark had to pick up the plate and walk away to stop him. It was like we have been starving him and he was so desperate for food- meanwhile he has a big bowl full of juicy chicken cat food dinner right there that he was ignoring. Meanwhile, Porter is watching the whole time, his mouth watering for that uneaten food *licking his whiskers* while he just ate his whole can of food already. That is why Mark calls Porter "Fatty Mc. Fat Fat" and Charlie is "Baby Fat" :)