My fat arse and I

One morning a girl tries on a pair of new pants, but they are impossible to zip. In the mirror, she sees herself as the fattest piglet the world has seen. To fix this, she decides to go on a strict diet. Because of hunger, she is more of a zombie, coming blindly to the fridge, which haunts her at night. In one of those moments, the Angel of United Bitches of Slimbuttlandia comes to her with a royal invitation to visit the Kingdom and to participate in a royal ceremony.

What is this ceremony? Are the Skinny Buttangels as lovely and harmless as they try to appear? How to find a way back home from The United Bitches of Slimbuttlandia?