Your classic mega douche who refuses perfectly good food on account of class 1 assholery. A douchetarian will find any way they possibly can to be a douche in any and all circumstances adhering to the principles of douchetarinitism.

Someone who has obscure dietary requirements, and is sure to make it known to everyone, rather than eating normal food like the rest of the world. ...Because let's face it, it's more than likely that they have no logical reasoning as to why they eat this way.

Somebody who harasses someone for being a vegetarian, even though said vegetarian doesn't shove their dietary habits down anyone's throats.

Practice of only consuming douchè
Someone who has surpassed the level of douchèbag.

Douchè brother who is very into themselves.