Fitsorexia 

An unhealthy obsession with being thin and working out, but also being fit at the same time. Often found in young women and teenage girls. Usually found in selfies on Instagram, Pinterest, Tumblr, etc.

"That girl is so fit!"
"No, she totes has Fitsorexia."

Fitsorexia by Tdawg_dawg November 26, 2013

Fatorexia

Opposite Anorexia. Thinking ones self is to Thin. Consuming food in order not to think your thin.

I think Becky is suffering from Fatorexia. She keeps saying that she is to thin, and keeps eating and eating. and She already weights about 350lbs.

Fatorexia by Scott67 March 31, 2008

fetusorexia 

A fatal medical mystery still yet to be discovered, fetusorexia affects the eating habits of fetuses, causing an extreme lack of appetite.

My fetus won't eat notin. It got fetusorexia!

fetusorexia by Dr. James O. Fetus December 25, 2007