I feel like there are a lot of cleanses and such happening right now. I've never formally done one. Well, I guess I "cleansed" myself of grains and dairy 6 or 7 years ago, but that probably doesn't count since I didn't join a group or anything...
A lot of people in my social feed are doing 30 days sugar free. A LOT of people. The "dry month" makes an appearance every now and then - 30 days without booze. One of the more respected Paleo bloggers, Dallas & Melissa Hartwig, are probably best known for their Whole 30 program.
Back when I eliminated those two "food groups" from my diet, I did so with no intention to ever re-include them as part of my nutrition - the 80%. They do make sporadic appearances in the 20% part of my food intake from time to time. Mostly in the form of the occasional slice of pizza, which I *always* regret, btw.
When I encourage my clients to try an elimination diet for 30 days (or 6 weeks or 6 months as the case may be), I do it with the expectation that they'll feel so much better they'll just continue to eat that way, only allowing that eliminated food back in (and regretting it!) as part of the 20%.
Because the thing that makes me scratch my head about the 30-day whatever-diet challenge is: what happens on Day 31? Would you say most people are going right back to their old patterns? Or do most people use the 30-day challenge to springboard into a forever change like I hope my clients do? And if so... do they just keep doing back to back to back 30-day challenges forever? Because I've seen this too on my social feed: a 30-day sugar-free challenge or cleanse that seems to happen month after month with no break in between. At what point can we stop declaring it a challenge and just sort of accept it as "this is just the way I eat now so I'll stop inviting you to be a part of my challenge group?"
I hope this doesn't sound snarky; I think people in my circle tend to think I get bent out of shape about cleanses and programs and challenges. I only do because I think the way we've socialized it just adds another fussy barrier to the simple act of eating nourishing food that makes us feel good. It isn't much different than painstakingly tracking calories or macros, in my books. Which, ew.