Refined Sugar is Best Protien Conservator
Fat is broken down into acetones in the blood which the body can
survive on if required. Gentlemen, you bodies crave and will have sugar. Even if you don't like it. Cortisol breaks down the amino acids in the body for the liver to transform into sugar (or glucose).
If you give your body no sugar then your muscles will be used to
manufacture it.
This is the cause for muscular loss prior to body fat storage loss.
Fat use is the final fuel to be used. The acetones produced by fat
burning cause the body to function at a lower level. (Fat use is to
the human body what watered down regular gasoline is to premium gas in a Harley-Davidson Motorcycle. It will run, but not very well).
For all of the negative crap published about refined white sugar
it is the prefered energy source for your body. Use of it will prevent cortisol from breaking down your muscles to make sugar.
Back to the first question. Muscle is much more dense tissue than fat is. Muscle weighs more. Muscle does more and it holds more blood for this reason. Fat merely sits there as a backup energy reserviour with no other purpose. Fat is lighter and holds less blood and water.