Huge output size for simple programs

[NX via Digitalmars-d-learn]

I compile a simple hello world program in C and the results:

hello_world.o -> 1.5 KB
hello_world (linux executable) -> 8.5 KB


Then I compile a simple hello world program in D (using DMD) and 
the results:

hello_world.o -> 9.3 KB
hello_world (linux executable) -> 575.9 KB


Then I compile a simple hello world program in D (using GDC) and 
the results:

hello_world.o -> 24.6 KB
hello_world (linux executable) -> 13 MB !!!

What's the reason for that? What makes D applications so much 
bloated?
Is this because whole GC implementation code is injected into 
executable or maybe libphobos.a being statically linked or is 
this because TypeInfo* ModuleInfo* stuff?