You could be talking about my 12 year old SS. My ss always had to find an outlet for anger. He stole alot when he was mad. Often strange things-my daughter's lip gloss, my bras and panties, etc. He also had the food issues. He would gorge himself at night-he would eat the boxes of jello, whole jars of peanut buter, he also would do the flavored oatmeal, whole boxes of little debbie snack cakes, etc. Sorry but I never really found anything to stop this. I even tried to make sure he got a sugary snack (ice cream for example) every night to try and prevent it. I tried grounding him from all snacks if he took one without permission. Nothing ever worked. He would do it nightly for a couple weeks and then it would abruptly stop for a week or so then start right back up. I never could determine any sort of pattern with it. He no longer lives with us and he doesnt do it anymore. So I guess I did find something that worked-he moved out.
If I reprimanded him for something-he'd turn around and hit, shove, pinch the other children even if they had nothing to do with it-just a way to take out his anger. He also had no remorse and continues to have none today. He denies any wrongdoing, happily lies to your face, and if your present evidence he just screams at you and then runs offs. I too was his primary parent. BM was involved but only eowe-she willingly gave custody to dh before he was even 1 year old. I truly believe this abandonment by their bms at such a young age causes an attachment disorder in these children. Since they have no attachment to anyone they are never concerned with following caretaker's rules and morals and they never learn to incorporate these into their own belief systems. Their primary concern is taking what they need, putting themselves first.

Holy Cow this sounds like my SD11! She does everything you mentioned. At Christmas my mom had sent gifts down for my SD's and she snuck and opened up each one. I found the gifts and the wrapping paper stashed in her room. When asked she lied and said she only opened two and of course her father believed her until I showed him the wrapping paper with the gift tags and then she finally fessed up and starting screaming and having a meltdown out of the blue. She steals lip gloss from me all the time. The last time I found it she said my BD did it. There was no way my BD did it. I don't get it. She is fed and has snacks and yet she will open a brand new box of something and takes all but a couple out of the box. I found all these individual coffee cakes in her backpack and I didn't even have one. And I specifically bought them for me to have with my coffee because no one else liked them...so I thought. She just doesn't own up to it. If its not nailed down, she'll take it.