I think the issue here is not whether an overweight instructor is capable of being an effective teacher, but rather to what extent that overweight instructor, who is supposed to be a karate "model" to his/her students, is an admirable overall example. Conditioning, diet, self-discipline, respect for others and oneself, are some of the many principles repeatedly taught through karate, but a grossly overweight instructor, regardless of the myriad of excuses I have heard over the years for their plumpness, are not optimally effective in teaching karate as a whole. Yes, an overweight instructor might be a great fighter "on the floor" (as one posts here), but the inability to control one's physical fitness (e.g., weight) diminishes your students' respect as well as your own credibility, no matter how awesome a fighter you are. This is where the big problem exists with overweight instructors. Ninanjurse hits the nail on the head in this thread. I could not agree with Ninanjurse more...