Then that's the reason why. The more you level up digestion, the faster the character digests
So with a 6 in digestion, the digestion speed is just near-instant? That doesn't make much sense, but then again, it's a game about making characters massive so ye. Just makes it harder to keep em fed, which, with one character nearly solely dedicated to giving happiness points (one of my characters has like, a 22 in happiness points), kinda balances it a bit.