I recently 'took up' bulimia again - it started as a teen and I'm 31 now. I didn't b/p for most of my 20s. But I've picked it up again as I'm gaining weight really easily for no reason (just age), and have a borderline anorexic diet when not b/p'ing. I'm pissed that I have to eat at a starvation level to maintain my weight now, and I've still gained, which is horribly uncomfortable. Body dysmorphia, sure, but what some people don't understand is that even a small amount of weight gain feels horrifically uncomfortable for some people, like wearing a tortuous fat suit.
It's a losing game, as there's no way to eat enough protein at my calorie level, so I'm bound to fall apart physically (I already have hair loss for no discernible reason, and lack of protein is supposed to make that worse).
I don't mind the bulimia, except that purging isn't fun. I don't judge myself for it or anything. I am also very bored, and experience little reward in life, so the eating helps. The rest of the time I nearly starve anyway.