I'm overweight, myself -- not morbidly-obese, mind you, but I do get the occasional remarks about my belly and unsolicited suggestions on what I could do about it. While negative attention about my body does make me feel awkward (to varying degrees depending upon the context of the given situation), I don't take it personally and get all butt-hurt about it.
So take my comment as self-deprecating humor and move-on.