Not that this is related to this comic or anything, but I just realized something about monster food.

There's that carnivorous plant monster in Grillby's that says monster food converts automatically into energy upon consumption, different from human food that goes through the digestive system. That makes sense.

But then there's this bit that kinda contradicts this:

In one of the conveyor belt rooms in Hotland, when you call Papyrus and Undyne, Undyne will talk about a time where she rode around on conveyor belts really fast. Papyrus then asks "DID YOU HURL?", and she says "Yeah, like 50 times! It was awesome!!!"

How...does a monster hurl if food is converted into energy upon consumption?

Would the food not be gone, thus it wouldn't be able to get thrown up again?

Do monsters even have digestive systems? Perhaps they do, since the plant monster said it "wanted to try human food some time".

Still, it wouldn't explain why Undyne would hurl, since they normally eat monster food, which doesn't "spoil, unlike human food". So there would be no reason why human food would still be edible if it's sitting in the dumps for too long.

I simply thought about the exchange and laughed inwardly during dinner, then I thought "Wait...monster food converts into energy, how can she..."

Any thoughts on this?