I dont get hungry, but as many people here, I do get a little sleepy... no matter what the time of day.
In fact, during the summer when I travel a lot, I have a tendency to get jet lagged like you wouldnt believe. >_> I end up having to go to bed 8 hours after I woke up just to get my sleep schedule straight. Since I cant take sleep-inducing drugs (I'm missing about half my heart--they'd kill me), I often just rub one out and fall right asleep within 10 minutes o_0
I wonder if any doctor ever prescribed masturbation as a solid sleep enhancer