Realistic is two weeks, you disappoint yourself otherwise even though you might have achieved a whole week or two. Make it two weeks and don't cut carbs 100% that's not helpful. I'm Amy case it's a yoyo effect.

In my experience the most useful diet to clean yourself, to reduce body fat without losing muscles is to only cut sugar and gluten 100% and eat slightly undercaloric. Mind your omega 3, vitamins, zinc, magnesium (taken in the evening) and you're good to go.