For those who don't know, a panniculus is where your belly drops. So in other words, what BMI does your belly start to hang at? Reason I'm asking is that I seem to be going in that direction. I am currently at normal BMI but I'm gaining weight quite quickly, as I am 10 pounds heavier than I thought.
I think it depends on things other than a BMI--body type, tissue elasticity, fat distribution, etc. It's not actually a "dropping" belly but rather a stretching of the tissues and formation of a flap of fat and skin that can hang, sometimes in an extreme fashion.
Many people put on weight, up to a couple pounds a month, but very rapid weight gain could be a sign there's something wrong, especially if you haven't changed your habits. Just how fast did you gain 10 pounds? Do you know why you are gaining weight so quickly?
And, yes, when your belly starts to overhang your belt depends on a number of factors.
It's probably not a specific BMI, but I am guessing it starts somewhere in the 28-29 range, or about 200-210 lbs., based on my own experience.
I've gained quite a bit of weight over the last few years. Initially I just got a little wider, noticed it in my hips and butt (pants fitting tighter). When I exhaled, my stomach didn't move that much. But then eventually I started sagging and protruding a little. Now, when I exhale deeply, my stomach expands out pretty far....it actually looks like that of a very pregnant female. I am on a mission to lose weight before it gets even worse.