Maybe there's something that you can take to simulate IBS...

I'm pretty sure when food goes right through me that I'm not getting any of those calories. Otoh, I have some idea of what types of foods (and how much) will trigger and the foreknowledge of that certainly reduces the joy of eating some foods I otherwise enjoy.

I still have trouble with calorie balance, but although I enjoy many kinds of ice cream, I have no problem going into an ice cream shop with friends and not ordering anything, even if I'm hungry. A 'single' scoop is way beyond my limit, and if I order a scoop, I won't order a scoop, take two bites and toss the rest, I'll eat the whole thing, so it's not worth it.

When I was doing bike commuting with real hills, I could eat anything, but now I work from home and can't convince myself to put that much time in the saddle just to eat whatever.