[Amadeus]

Um, that is simply not true Jim. You'll lose a little muscle mass the first few days, but research shows that you will primarily use fat and bad tissue during your fast unless you are below 5 percent body fat.
Think about it, not only does research prove what you are saying is not factually, but look at it from a biological stand point. If what you are saying is true about using muscle as energy, why would the body use the muscle instead of the fat first? Why would the body save the fat if it knows it can use the muscle as a last resort? The body would evolutionarily save the muscle in case of a fight or flight situation.
I've had my fat and muscle percentages measured before and after a three week water fast. I hardly burned any muscle during the fast (less than a quarter percent) and burned over 4 percent body fat.