Kitten poops on ben when hungry

My kitten is eight months old. He has been very food-motivated and gluttonous since the first day we got him (four months ago). We can’t leave any food out or he will eat it—he even got into a bag of flour one time and ate some of that. If we are cooking or eating, we have to lock him in our spare bedroom or else he will jump onto the counter/table relentlessly and attempt to eat our food. His litter box stays in that room, as does one of his water bowls and one of his cat towers. For the last three weeks or so, anytime we put him in the guest room while we are cooking, he will scream for a few minutes, finally get quiet, and then poop on the bed (in protest?). We keep his litter box very clean, so I know that isn’t the problem. Tonight, instead of putting him in the guest room, we decided to take our food into our bedroom to eat in peace. Our kitten complained outside our door in the hallway at first, but then got quiet. After I was done eating, I opened my door and noticed he was sitting outside of the guest room. I peered inside the room and saw that, again, he had pooped on the bed. Is he doing this maliciously, or to communicate with us that he’s hungry? Could he be sick? Any thoughts are appreciated! (Note: we were away for 5 days last week and my father-in-law came to feed the kitten while we were gone. The kitten did not poop on the bed at all while we were away!)