American here. I can recognize that it's considered rude here to admit someone is overweight, even if they ask.

So I would never answer this question to someone who didn't love me. And even then, they get offended, even though they ask.

Instead, my answer is, "Nope, not gonna answer that." And then they get mad anyhow.

So the comment above about the "trap" is correct. That person started the rudeness, but they won't take the heat for it.