My dog is too obsessed with food

I have a one year old standard poodle female, and since we brought her home she eats absolutely everything. She has to be crated because she will steal food and get up on counters if she has the opportunity. She knows she is not supposed to do that because she gets very guilty. She also can’t help herself from stealing and eating tissues, dirty towels and underwear. And if she has something she really wants, she may get agressive over it. We stay pretty diligent in keeping her away from food and the other inedible things she likes, but sometimes she still finds something. I’m scared she will get something that will seriously hurt her, but she will not stop eating everything and anything. She is fed about two to three cups of food a day, dry food with occasional treats like chicken and cheese. She can’t have anything other than dry food because she will have liquid poop. Which is another reason why she can’t be stealing food, the clean up that follows is awful. Please also don’t suggest training because we’ve exhausted that option, it only works when we are in the room.