I had completed a 10 day Water Fast earlier this month, and the loss on the scale was 16 pounds. BUT the same as you my fat % went up even though the scale numbers were down. So, I have found for me that fasting doesn't work. I now weight train 3 days a week with 3 days of aerobics and I eat every 2 to 3 hours. In a short time I notice a difference compared to when I was fasting. I made myself a little motto, when I fasted, my fat cells overlapped and shrinked my muscles, but when I weight train, my muscles melts the fat, (ie muscles burn fat) which makes me more leaner.
Not here to say fasting doesn't work, it just didn't work for me or shape my body as I had hoped. So, I have thrown out the scale and I only work through measurements. And I have done the juice thing too, and I looked and felt bloated, but it has worked for some, check out the fruit fast forum.