A petition as part of the people that like weight-gain fetish games, it would be nice if the character would get fatter if they over-indulged. A NPC teases this idea at the restaurant, telling you to drink water to not gain weight and plus-size is already an existing tag in the game (but it´s limited to just being able to interact with a plump NPC). It could also contain some funny interactions with some game mechanics such as a skinny character being more agile than an obese character or a plump but not morbidly obese having better chances at charisma due to their curvy figure.
Clothes being too tight, getting stuck in certain places and lewd interactions due to being squishy are definitely things that would be fitting to this game