Memes

Eating a lot is not the original meaning of gluttony in Catholic mythology. If you look at some of the self-evident deadly sins like envy, pride, greed, or wrath, you see these don't refer to a specific action you commit, but rather an abstract emotional attitude, a "pre-sin" from which actual sins stem. For instance, sloth is not you spending an afternoon on the couch, it refers to a general lack of goals and eagerness to the point that it is harmful to you; and lust does not refer to having a lot of sex, it refers to your thoughts being dominated by desire. In the case of gluttony, it refers to a general obsession with having things in excess of what is good for you.

On a side note, in German traffic law they later came to mean the seven ways of wrongful driving that warrant criminal prosecution: Not respecting right-of-way (pride), wrongfully passing other cars (envy), driving wrong at pedestrian crossings (gluttony), driving too fast at an intersection (greed), not driving in the right lane (wrath), attempting to turn on motorways (lust), and failing to mark defective cars in traffic (sloth).