Why? It is just a fact. The guy is absolutely overweight. Who cares? Lots of people are overweight. This is also a fact. Are we not supposed to acknowledge that?
I'm not the parent commenter, but I feel the same way. Just because something is a fact (although arguably fat doesn't sound very factual) doesn't mean it needs to be discussed during an interview. If someone started Quizzing me on the chemistry of rubber tires for a software dev role, I'd walk too. If someone started listing off the various kinds of sausage there are, I'd walk too. It would make me feel like I'm not taken seriously at best, or that I'm being scammed at worst.
Beyond that, if I looked east Asian, I could also see myself walking on this question for another reason. It would feel like a comment on my ethnic background, which has no place in an interview.
