One of the scariest and most vicious men I ever met was quite a porker too.
When I first met him he was a sergeant in a sister squadron, and easily weighed seventeen stone, but he could easily keep up with me on any regimental runs we did, and I was supposed to be a bit of a racing snake in those days (more like a weeble now). I don't know if he was brave in combat as I never saw him, but his combat history was quite a long an impressive one for cold war times.
On the other hand Roy P Benavidez wasn't all skin and bone either!