Is 36-48 hour fasting something that you do all the time or just once in a while?

Hi everyone, I've done OMAD for weight loss in the past and recently decided to do it again.

I see many people on this sub doing 36-48 hour fasts, and I wanted to know if this is something you do just once in a while, or if you do this constantly (meaning that you fast for 36-48, then eat, then immediately fast for 36-48 again, and so on...).

Thanks in advance :)