One of Schopenhauer's contentions was that perception was affected by desire, often in unconscious ways.
The classic example is where two men walk into a room, one is hungry, the other isn't. The man who isn't hungry first notices the art on the walls, the one who is hungry notices the food on the table.
Turns out that this not the only way a hungry man's perceptions are altered.
It seems that a hungry man will find larger women more attractive than when they aren't hungry! So much like the amount of beer affects how attractive a man will rate a woman so will the amount of pretzels.