Well I think your analogy would be better if they could also chew and swallow rapidly, but then their digestive tract took inordinate time to process the meal... (^_^);
That wouldn't be a better analog at all since it wouldn't be making the point I wanted to make, it would just be rephrasing what they stated using the same metaphor.
Imagine if someone said they could eat super fast because they could shove food in their mouth fast, but still took a long time to chew and swallow.
Same thing.