Lean Body Mass & Body Fat Percent

Lean body mass (LBM) and body fat percentage are ways to quantify the physical composition of our bodies.  It helps us compare our muscle and bone mass to our fat.  Rather than measuring a diet's success on weight, it makes much more sense to track LBM and fat percentage.  Especially if you are exercising, you might find your weight has plateaued but your waste-line is shrinking.

There are numerous methods for calculating your lean body mass and percentage of body fat.  I would love to have someone help me to try all of these methods so that we could compare accuracy.  If anyone knows where you can have each of these tests performed, please let me know.  I am stuck using the Covert Baily formula which only requires tape measure and a scale.

1. A professional will use calipers to measure the thickness of fat in various places on your body. The result is supposed to have a margin of error of only 4%. I have no idea what formula they use nor what points they measure. 
2. Because muscle is more dense than fat, you can also be placed in a tank of water to see how much volume you displace. There are also machines that can measure air displacement. 
3. Bioelectrical impedance analysis (BIA), which uses the resistance of electrical flow through the body to estimate body fat. I have no idea as to the accuracy nor where you can get this test.
4. Apparently you can also use MRIs, CT scans, and ultrasounds to somehow estimate lean body mass as well.
5. A simple tape measure and scale can also be used. The most commonly accepted is the Covert Baily formula to estimate body fat percent.  You can then multiply your weight by this to get the total weight off fat & subtract this from your weight to calculate your lean body mass. I am uncertain as to it's accuracy compared the other methods mentioned above. None are perfect as our bone density will vary with age and there are other factors.

The Covert Baily formula is as follows:

Women Over Thirty
hips + thigh - (2xcalf) - wrist = % body fat
Example: hips = 39"; thigh = 23"; calf = 13 1/2"; wrist = 6"
39 + 23 - (2x13.5=27) - 6 = 29% body fat

Men Over Thirty (example based on my own measurements)
waist + (1/2 hips) - (2.7xforearm) - wrist = % body fat
Example: waist = 55"; hips = 56"; forearm = 15";wrist = 7.75
55 + (0.5 x 56 = 28) - (2.7 x 15 = 29.0) - 7.75 = 46.25% body fat

Then, to calculate lean body mass:

TotalWeight - (TotalWeight * PcntBodyFat / 100) = LBM
Example: 335 - (335 * 46.25 / 100) =  180 pounds other than fat.

The waist should be measured at the belly button, not necessarily the belt line and the hips at the widest point   below the belt.

Regardless of which method you use, it gives you a physical attribute to watch while dieting that will tell you if you are losing fat or muscle.  It also will help you know you are losing fat even if your weight has not changed or even gone up.

With this knowledge, I am almost ready to begin my diet.  I have a little more research to do on calories and base metabolic rates.  I will use these to determine what my caloric intake should be to maintain my weight and also to lose weight.  I will post this information within the next couple of days.