Sure, there can be situations out of your control - I, for example, do believe that my genes aren't helpful to my weight based on family members and anecdotal evidence, but at the end of the day if I really cared I'm perfectly aware that I could be skinny, I just happen to chose to eat great food, and too much of it, and do far too little exercise.
If you mock me for being gay I might be offended, but for being fat.. that's my own damn fault, I know how to stop being fat but I don't care enough to do it, currently. If anyone wants to laugh at that, give a shit,