Body Composition -  The human body contains many of the elements of the earth, twenty five of which appear to be essential for normal physiological functioning. Most of the human body , around 96 percent, consists of four elements (carbon, hydrogen, oxygen, and nitrogen) in various combinations.  These four types of elements are the structural basis for body protein, carbohydrate, fat, and water. The remaining 4 percent of our body is composed of minerals, primarily calcium and phosphorus in the bones, but also including others such as iron, potassium, sodium, chloride, and magnesium (Nutrition For Health, Fitness, & Sport 8th Edition, Melvin H. Williams).

Total Body Fat - The total body fat in the body consists of both essential fat and storage fat.

Essential Fat is necessary for proper functioning of certain body structures such as the brain, nerve tissues, bone marrow, heart tissue, and cell membranes. Essential fat in males represents about 3 percent of the body weight. Adult females also have additional essential fat associated with their reproductive processes. This additional 9-12 percent of sex specific fat gives them a total of 12-15 percent essential fat, although this amount may vary considerably among individuals.

Storage Fat is simply a depot for excess energy, and the quantity of body fat in this form also may vary considerably. Some storage fat is found around body organs for protection, but over 50 percent of total body fat is found just under the skin and is known as subcutaneous fat. Cellulite is primarily fat. The appearance of cellulite is much more common in women than in men.

Other storage fat is located deep in the body, particularly in the abdominal area. This deep fat is referred to as visceral fat, which is associated with increased health risks.

Fat-Free Mass primarily consist of protein and water, with smaller amounts of minerals and glycogen. The tissue of skeletal muscle is the main component of fat-free mass, but the heart, liver, kidneys, and other organs are included also. A more common term often used interchangeably with fat-free mass is Lean Body Mass. Muscle tissue is a "metabolically active tissue" requiring more energy and thus causing you to burn more calories even at rest. Muscle is your friend.

BONE MINERAL:

Bone gives structure to our body, but it is also involved in a variety of metabolic processes. Bone consist of about 50 percent solid matter, including protein and minerals.

BODY WATER:

The average adult human body weight is approximately 60 percent water, the remaining 40 percent consisting of dry weight materials that exist in this internal water environment.

* Body Composition may be influenced by a number of factors such as age, sex, diet, and level of physical activity. Age effects are significant during the developmental years as muscle and other body tissues are being formed. During adulthood, muscle mass may decrease due to a decrease in physical activity. This is why resistance training is a vital and important part of an exercise program. A resistance training program can prevent a decrease in muscle mass and even increase it. It is a no-brainer that diet can affect body composition. For example, habitual overeating may lead to increased body-fat stores. Physical activity is also very influential, with a good exercise program, a person can build muscle mass and lose fat.

How do you measure your Body-Composition & Body-Fat percentage?

There are various ways to test your body composition. Some are more expensive than others. I am listing a few here:

1. Skin-folds - indirectly measures the thickness of subcutaneous fat tissue. Skinfold

Measurements are highly correlated with body density measurements from underwater

Weighing. Percentage body fat estimated from skin folds is valid and can be reliably

Measured by properly trained personal trainers. The equipment used is a “Skinfold

Caliper, Tape measure, and marking device such as a pen.

 
2. Bioelectrical Impedance Analysis - works by the measurement of the amount of

Impedance or resistance to a small, painless electrical current passed through the

body between two electrodes which are often placed on the wrist and ankle. The

idea or concept is that leaner people conduct this electrical current with less resistance

than those who are carrying more adipose tissue.

 
3. Waist-to-Hip Girth Ratio - Although not truly a measure of body composition, the

Measurement of the waist -to-hip ratio is a valuable tool for assessing relative fat

Distribution and risk for disease. People who have more fat in the trunk, in particular

abdominal fat, are at increased risk for a variety of cardiovascular and metabolic

diseases. 

4. Body Mass Index (BMI) - Body Mass Index does not measure body composition, but it

may be useful as a screening tool to determine whether or not one is overweight or

obese. Overweight and Obesity are not synonymous terms. Individuals who are athletic

very muscular may have a higher BMI score than normal and not be truly overweight

or fat.

 
Calculating BMI

Non-Metric Version: To calculate BMI using non-metric units, use this formula:

 [Weight (pounds) ¸ height squared (in.² )] X 703

 For example, a person who weighs 164 pounds and is 68 inches (or 5 feet 8 inches tall) has a BMI of 25:

[164 ¸ 68² ] X 703 = 25 

Classification of Overweight and Obesity by BMI:

(From NSCA’s Essential’s of Personal Training Roger W. Earle & Thomas R. Baechle Table 19.1)