One of my professors - who did not see much value in nude models - once told me about how his own instructors used to pay people from the skid row part of town to be nude models apparently to keep down libidos AND give students something more challenging to delineate. He was a gifted raconteur with a lot of good stories that ranged from his WWII service (8th AF) to the world of art museums, and some of what he said about human nature has proven valuable to me to this day.
Mr. niteowl77
One of the nude models at my school was an anorexic dope addict. All art majors had sketches of Anorexic Annie in their portfolios.