Logic tells us that as long as you are decreasing your calorie intake, you will lose weight. Of course, it is a different way that the body will lose weight. (Do an internet search on ketosis).
But if your goal is to lose weight, try and figure out what the caloric intake is of what you juice as opposed to what you normally eat, and as opposed to the calories you need to operate in a day.
Go to fitday.com it has a great system on there, including a journal, charts, caloric values and it can keep track of your weight loss.
Also, there is a fasting for weight loss forum, very friendly and different kinds of fasting. It's also somewhat popular, so you don't wait too long for questions to be answered.