Cherry:
It depends on the type of job and how big you want to get. Myself and my colleague are both at least 50lb overweight and we have a pretty active job. We work in a furniture warehouse for a charity and walk around 11-13,000 steps a day, whilst carrying furniture (there is no forklift or anything, just us two). Of course so much heavy lifting makes you very muscular, so carrying a bit of extra weight isn't a problem. If I was thin I'd be a very odd shape for a girl, with huge shoulders, thighs and ass, but having a big belly and boobs balances it out. If your job involves a lot of walking but not much lifting, then being fat would be more difficult and slow you down.
Sounds like we do the same kind of job.
I just was certified (I watched the video) to operate our forklft, but most of the time I'll leave it to someone more experienced.. I do try to get in some practice under the correct situation (if you know what I mean).
These same movements also burn calories, and the muscles will allow you to burn even more.
