Well, size hasn't always been a deterrant for fighting ability. There are some great Kung Fu men like Hung I Hsiang ( http://en.wikipedia.org/wiki/Hung_I-Hsiang ) who were renouned for their fighting ability despite his girth. Same goes for one of his teachers Wang Shu Chin ( http://youtube.com/watch?v=vVg6De9Rk0Q ) And Let's not forget my favorite convex abdomened karateka Motobu.
1216339648.GIF I think that one does not need to be in that slender of form in order to be able to fight. As technique improves, so does effort. the more efficient one becomes, the less exertion is required and the fewer calories are burned.
