Feline PTSD rage-eating ... oh noez
. Poor Bubbles.
Have you experimented with putting out dry food / crunchy stuff for him trashy? Maybe if he knows there IS food there all the time, if he really wants it, it might calm his rages. And dry food is not SO appetising that he'll eat a massive bag's worth of it in one go, surely? might be worth a go if you haven't tried it already
Peggy would eat her own weight in dry food if I let her. But that's not a bad idea, to leave a bit out all the time.
trashpony Orijin is a very good brand, I believe it has the highest meat/protein content on the market, no grains, theoretically they will therefore need less as high quality protein gives them the fuel they need, rather than stuffing them with carbs.
There is of course the option of diet food. Royal Canin Ultra Light (wet or dry) has been my go-to and both Charlie and Peggy lost weight on it (the wet). Apart from Sheba (grrr) and dry it's Peggy's favourite wet food.
But as well as addressing what he's eating, you'll probably need to look into providing a way for him to take out his frustration and/or be distracted by something else when he goes into one of these food rages. It's hard work, but there are no short cuts to properly sorting out this kind of thing I'm afraid. It might mean being actively engaged in playing with him when he starts to act up, find a toy he loves (I highly recommend 'Da Bird') and invest some time in letting him work out his energy. It can be a mixture of wanting food
and boredom
and stress, so making sure all his other needs are attended to is probably a key part of this. I expect life was pretty exciting (and dangerous of course) while he was away, and the lap of luxury, even if he has access to outdoors, probably doesn't always cut it after getting used to the cut and thrust of the mean streets. Of course, primarily it's going to be an issue of anxiety over food insecurity, so the food thing needs to be dealt with as you know, but making sure everything else is sorted too can only be a good thing - plus getting in there with toys etc when he starts to get destructive is just a good way of distracting him so he takes that anger out on something else.