Nofbar:
It can depend on the job. If you work at a restaurant, there can be lots of cheap or free food available. It's how I gained around 100-150 pounds.
I live with someone who does late shifts at a small supermarket, it's common for them to bring nearly expired food home which we either need to eat or freeze.
Also the amount of physical activity can be an issue, my retail job is fairly physical which I believe is a contributing factor to why I struggle to gain, even when I really push myself.
At the same wage but if I was idle I reckon I would more easily gain weight.
