American High School Students Are Reading Books At 5th-Grade-Appropriate Levels: Report | Eclectic Technology | Scoop.it
High school students today are reading books intended for children with reading levels far below those appropriate for teens, according to a recent report.

Renaissance Learning, Inc. has released "What Kids Are Reading: The Book-Reading Habits of Students in American Schools." The data in the report comes from "the Accelerated Reader Real Time database (which) includes book-reading records for more than 7.6 million studentsfrom 24,265 schools nationwide who read more than 241 million books during the 2010–2011 school year.

Based on the ATOS readability formula (which looks at vocabulary and sentence complexity) the reading level of many books used in high school are often at 4th to 5th grade level. 

This article lists the top 20 books read among US high schoolers in 2010 -2011 and additional information. The complete report is available as a pdf file at 

http://doc.renlearn.com/KMNet/R004101202GH426A.pdf ;