Do you know about readworks.org? It's one of those resources that I use often. It's so fantastic that I just assume everyone else must know about it, too! In case you don't, please do yourself a big favor and follow the link. You'll be amazed at all of the COMPLETELY FREE K-12 reading passages (fiction and nonfiction) with related questions, standards-aligned units, and lesson plans. There are even paired fiction and nonfiction passages.
On the ReadWorks site, I found articles about health at different Lexile levels. First, students read a passage at their level with a partner. Then, we changed things up so that students partnered with a person who had read the other article. The partners reread both articles, then completed a VENN diagram comparing and contrasting the information from both articles. It was easy to differentiate.
ReadWorks has saved me a lot of time and money. I strongly suggest that you check it out!