I think back in 2015, I found a thread where someone posted code for a weight estimation plugin; I got it to work again and posted a reply, but no one noticed.
Well just now I decided to fix and finish it. It automatically finds surface area + weight + BMI of the character. Originally, since the existing surface area calculation didn't work, I used a workaround by having a textbox to manually enter surface area (obtained via blender, with its 3d print tools addon). I opened it up again today and found that the problem was that it didn't recognize the function from mesh_operations.py. I didn't/don't know how to import it, so I just copied all the functions from mesh_operations.py into my file. (If anyone knows how to fix that, feel free to do so. )
Tested in makehuman 1.1.0.
edit: also, it gives the wrong results if you check "hide faces under clothes".