Being over a healthy weight, means you are obese. If you are obese to the point of it infringing upon your life, you are morbidly obese. In any sense of the whole matter, obesity is a monster. When you are obese, it takes more than a strength you can imagine to turn the ship around. It takes a power of body and soul together.. it takes such determination that many times help is needed because it can be a matter of life or death.
So what this poem means is this, if you do not tap into the strength needed to become healthy or fit, it could very well kill you, and if it doesn’t kill you, you will be stronger having succeeded.