having too much fat is unhealthy- you can't run as fast, you get tired more easily, your heart has to work harder to keep you going,you are at a greater risk for MANY diseases like diabetes, and you could die sooner. You can't fit into as small of places (like airplane seats) or if you can fit it is more uncomfortable. If you have too much fat on your stomach you will have worse posture because your back will be stressed and also the lower back gets sore. If you have too much fat you can't see your muscle even if you are really strong. And that's just a scratch off the surface!