Why am i ripped and fat at the same time?

my upper body from my chest up and from the waist down are ripped like pretty big, but then i have sort of a beer gut going on in the middle wtf??? if i wear a cutoff t shirt i look great but if i take off my shirt people look at me like what are you doing?? how does this happen that my upper and lower body are cut and my mid section looks like a 50 year old trucker?