Casual Gainer:
I live with someone who works at a small supermarket who regularly gets free food which would otherwise end up in the bin, will see/buy discounted food and of course has a staff discount.
The job can be quite physical though.
Occasionally they get me something though, such as the 1000kcal bag of cookies I just ate.
MottiF:
I don’t know, I didn’t gained much weight, working as cashier on a supermarket.
I would say that working on a Pizza place did. The owners would let us eat as much as we wanted and I found myself gorging on a lot of pizzas, made me hungrier and I ate a lot, although I gained just a little, maybe because it was years ago when I had faster metabolism.
YMMV, I reckon 90% of their freezer is free food and even then they still use some of mine.
If they actually ate enough of it, I reckon they'd start to put on some weight.
Just working in a junk food place doesn't guarantee free food either. IIRC someone I knew only got a free meal on extended shifts.