Side note; the documentary “Science Of Fasting”, found that a normal weight person has enough fat to fast for 40 days. Meaning an overweight person has more than enough fat to fast for that long. That being said - I believe longer fasts should always be followed up by a doctor.
My 2 cents. If it’s a person doing it under doctor’s supervision in a safe manner and has gotten good results after finishing a long fast, very interested to see it if the person is detailing all safeguards and the process.
If someone is randomly putting up a post of a few lines that they are going to start a 100 day fast without any prep or consideration, that falls under promoting dangerous fasting.