The characters' capacity are softlocked to 100% ; once you reach 100%, they'll generally refuse to keep eating until you let them digest. However:
- It is possible to feed them up to 99%, then finish with a very filling food to shoot past 100%.
- When you invite a NPC with a feeder trait over (presently your only option would be Emma after completing her "feeder questline"), that NPC can feed your character a few times. When you do this, it bypasses the fullness check, so feeder NPCs can feed your character past 100%.
Also, something worth noting: your character's maximum capacity will increase as you feed her and will unlock extra sprites where your character's belly gets much bigger (in total, there are 7 fullness steps including the "empty" one). It's a bit of a grind, but the more stuffed she is, the more her maximum capacity will increase, and trying to go past 100% will make this process a bit faster.