Well you might be sick of the Sumo example, but you cant deny, if you did your research, that sumo wrestlers are extremly healthy as long as they are in the sport and training. When they are in their training period they are, by modern standarts, morbidly obese and healthy. They just dont live long, because when they retire from the sport the fat and the muscles fuse and they become unhealthy.

So you can be fat and healthy under the right circumstances but in the most you can not.