You will typically gain back between 5-8lbs because your gut will hold food. But you won’t gain back weight from fat as long as you refeed correctly and you eat appropriately after. Choose foods that are low glycemic, low carb, and/or keto.
It depends on how and what I eat. I’ll never fast between late November and January ever again. However outside of that range, about three months for 5-8lbs and almost always the result of overindulging on fast food.
I havent fasted for more than 4 days but I’ve been 3-4 day fasts regularly. In my experience, you gain like 5-6 pounds back but its mostly water, but at the same time you lose it quickly with a few cardio sessions
Just completed my first 7-day fast - lost 14lbs and gained ~9lbs back within 2 days. I didn’t eat so well though so that definitely contributed.
That added weight seems to come off easy though - doing another fast now and already lost much of it in the first day.