I have not, but isn’t that basically what patients do on a bariatric surgery diet - the diet patients go on before bariatric surgery to reduce the size of the liver so it is not in the way during the surgery. There are plenty of examples posted online by doctors/clinics that perform bariatric surgery. I would assume Mayo has their version. The diets can be extreme because the patient needs to shrink their liver in a short period of time - IIRC some of the diets are for as short as 2 weeks - but no reason someone not preparing for the surgery couldn’t do a less extreme version and take more time. And assuming the diet is from a legitimate source like Mayo it should be safe given the number of patients undergoing bariatric surgery.

You probably could also just follow the Mayo Clinic Diet < diet.mayoclinic.org>. You can just buy the book (and daily journal) for the diet if signing up for the program is more than you want to spend and you don’t need the prodding. There is also a diabetes version of the book. (And no, I don’t work for Mayo’s marketing department.)