Is there a name for the non-fiction content in which the author tells the story by chronicling some journey they set out on for the purpose of writing, documenting their journey? Prominent examples that immediately come to mind for me are Super Size Me, The Year of Living Biblically, Kumaré and I know there have been many other authors, documentarians, journalists, etc. that have decided to tell stories by setting some challenge and documenting it.
The memoir genre seems too large to describe this form of storytelling although it does seem fitting to consider it a sub-genre of memoirs. I was thinking something along the lines of investigative memoir?
Anyway, does a name for this already exist? If not, what would you call it?