;-) there could have been only 3 outcomes of your venture with Joe:
1.) with your info-news promotion: the gullible that think buying such a plan would work for everyone & contribute to the possible wealth of Joe. Let's face it, with a common-sense plan, for those that are determined & with long-term grit, one could not only lose weight (some Mainly want to look great or get pecks) but also stop smoking, detox, even rehab from heroin addictions.
2.) you try "something extraordinary" out and found that it worked and become the next guru and write a book about it, and become next Neil Strauss & or Scott Carney, sadly exercise & diet is not rocket science, it's a numbers game, need a good number of credulous public to buy the book/seminar/ or pay with their attention/mind-share/admirations; sounds to me there is no shortage of them already based on your article (I've never heard of Joe nor will I seek him out, just like Jamie the Olive.)
3.) you get paid for your article, write something interesting (this article), and investigate about something/someone else later. OR you self-challenge (just like you mentioned nudge) and devise something great in the line of PUA or WimHof methods and be the next focus of the article (& be adored by women & be next paper millionaire) by another journalist completing the circle.
everyone has their own challenge/journey; for those that can afford it, get someone to tell you what you need to do. For other successful people that a self-determined, its very simple a go/no-go decision= Once made, no hmm or ahhs.. and 'JUST DO IT'!
Think we have spent enough time on Joe and my comments already.