I've lost a lot of weight, but I juiced fasted for a week, ate a diet of mostly raw salad for the next week, then went on another juice fast for almost another week, before starting to eat cooked food again. I wanted to totally detoxify, so losing a lot of my body fat was going to be a side effect I'm willing to put up with for the short term until I can build myself back up. Lots of toxins are stored in your body fat and I'd rather be temporarily skinny any day of the week then go through one more day of those horrible hypoglycemic-like symptoms now known as toxic hunger!
You don't have to juice fast for as long as I did if you're worried about losing weight. You might only need to juice fast for a few days until your toxic hunger symptoms go away, then maybe go mostly raw and mostly vegetarian diet for a week or so before introducing meat back in. I'd start with fish first since it's easier for your body to digest than other meats.
My symptoms were gone after the first two days of juice fasting and have never came back.