I haven't noticed any muscle lost -- but then again I put on muscle /very/ easily (a bit too easily actually, I get hypertrophia if I do too much sport). For energy, it turns out your body /does/ have some to burn, and once you made the switch to burning fat, well, usually there's a nice source of energy... I also wonder if you don't get a small dose of adrenalin in too, which would explain the 'high' you get after a couple of days.. but don't quote me on this..

But as I mentioned, the fruit juice input in the morning does help get the day started. Oh, and the coffee contains some nutrients too, so it's not like I'm totally starving.