Is there a name/genre for books and documentaries like Super Size Me, Year of Living Biblically, etc..?
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?
I'd just call it by the say-what-you-see name of "Personal challenge documentary".
As @JEL says in the comments to the question, it is in the "Performative" category, according to that popular categorisation at least (eg https://www.videomaker.com/article/c06/18423-six-primary-styles-of-documentary-production). You could also call put it into the "Investigatory" category, since the film maker is investigating what it's like to live in a certain way for a year, or whatever.
But, "performative" just tells us that the film maker is the subject of the documentary, and "Investigative" just tells us that something is being investigated, and suggests that the thing is something external to the film maker. Neither really tell us anything about what (s)he's doing. I think "Personal challenge" fits the specific set of documentaries mentioned in the question.
I think most people would "get" it - if you said "I'm going to make a personal challenge documentary" they might say "Oh, like Super Size Me or something? What are you going to do?".
"Memoir" definitely isn't right, as a memoir is someone looking back on their own life, like re-reading a diary, whereas this style of documentary follows the action as it happens.
Self-experimentation movie or documentary, with an example of use here, citing different avatars of "Super * me". The first term refers to a situation:
in which the experimenter conducts the experiment on himself or herself.