That makes sense. Girls already passively gain if they're addicted to Dizzy's, so if I do add a gluttony stat, perhaps that could just impact date behaviour.
I'm sure this is all moot since it's probably a ways away, though I do think the appeal of the gluttony stat would be the way it adds some autonomy to the girls. The Dizzy's addiction is already one of my favorite features in how it adds passive weight gain, so maybe it's more a question of balance or tuning?
I certainly like the idea of making the girls more independent characters who make their own decisions in the background of the game. The next update will include a little more in this direction, but perhaps they could have their own things going on that they could tell you about, such as a failed diet or having to size up their clothes.