Blender to Unity

I am using a character that I have created in MH 1.0. I export the mhx file from MH to blender. Make some mods to the clothes. Fix the holes. Then export a fbx file(armature and mesh), to use in Unity 4.3.4. Load into Unity. I get a bounce of GZM.?? files. Also a lot of empty meshes. Whey are these files being generated by Blender? When I use Mecanim to create the avatar and put into my scene, I delete them and all is good. Is there anyway to eliminate these superfluous files?