Well, I'm on day 3 of JUDDDD. I'm a daily weigher so you might be interested in my stats.
After day 1 I had lost 3lb. I've weighed this morning after day 2 and put on 2lb, so I'm now one pound down.
Unfortunately, since I've had a horrible cold all weekend and it's not going away, I put on 2lb since last week (it's pure water retention, my feet are so puffy they are uncomfortable) so I'm actually a pound up over last week. That's no worry, though - that will go away on its own. Figured I should mention it, though, so that in a few days when I go "wow, I lost 3lb overnight!" you'll know I'm not some kind of medical miracle.
On day 1 I ate approx 1000 calories and I did one Body Combat class and one Body Balance. On day 2 I ate approx 2500 and I did 2 Body Combat classes. Average daily calorie intake = 1750, average daily calorie burn from exercise = 600ish (didn't wear a HRM so this is a bit of an educated guess).