This fucking fat bitch walks into the doctor's office and says, "Doc, I have these two large lumps in my breasts." The doctor steps forward, takes a squeeze and says, "those are your knees you fat fucking bitch!"
Making fun of people struggling with a health-threatening condition -- which obesity is -- is not amusing.
It's just a joke. I don't find anything wrong with fat jokes, I mean what else can you do with them?
One shouldn't fat shame or make fun of people who are overweight, or anyone based on their physical appearance. People who are overweight are just as worthy of respect as anyone else and making fun of them can truly hurt their feelings and self-esteem.