It's not so much a "shouldn't have to" as it is a "shouldn't".  I don't think it's a civil liability issue (at least in the US...Not yet, anyway), but it's just a bad idea to do so.  Fat people are everywhere, and they're apparently a very vocal group because they are constantly feeling put out because they are so damned fat. Ugh.    A classic case of: "I applied to a job where I absolutely represent the exact opposite of what the company is selling and I DIDN'T GET THE JOB!!" kind of scenario.    It would be like a fit woman applying to be a "plus sized model".  They'd never hire me or any other shitlady, sooooo....(logic warning), I would not apply for the job.