Post stories about a girl being forcefed a lot of food.

All the stories by logitechk1 on deviantart have numerous force feeding scenes and all center around forced weight gain.

Changed thunder by sci-sinc on DA is an absolutely great stuffing and force feeding story.

I also highly recommend Logitechk1's stories, especially "Dangers of the Dark Web" and the two parts of "Power of Propaganda". "Adding to Amber" is very good but more romance oriented.
Moob22 on DA also does quite similar stories (Feeding Alba, Feeding Gaga, Feeding Amy).