Body Composition and Obesity Index

   
Body Composition
Body composition can be divided into lean body mass and body fat. Lean body mass is fat - free weight. It includes the skeleton, water, muscle, connective tissue, organ tissues, and teeth. Body fat includes essential and nonessential fat stores. Essential fat includes lipid incorporated into organs and tissues such as nerves, brain, heart, lungs, liver, and mammary glands. Nonessential fat exists primarily within adipose tissue.

Measuring Body Composition
The morning weighing ritual cm the bathroom scale is really an attempt at estimating body composition. Using this method, it is impossible to determine accurately if a fluctuation in weight is due to a change in muscle, body water, or fat. The method also cannot distinguish between overweight and over fat. A 260 - pound muscular football player may be overweight according to population height - weight standards, yet actually have much less body fat than average. A 40 - year - old woman may weigh exactly the same as when she was in high school, yet have a considerably different body composition.

Anthropometric
Anthropometric assessment of body composition uses various superficial measurements such as height, weight， and anatomical circumferences. Of these, height - weight is by far the most popular. Height - weight tables, periodically produced by insurance companies, are inadequate, however, because they are subject to individual interpretation they require people to decide if they are of small, medium, or large frame. In addition, they do not take into consideration individual differences in lean body mass and relative fat.

Body Mass Index (BMI)
The body mass index is weight/height², and it is moderately correlated to percent fat. Because data are easy to collect, this index is widely used and reported in large epidemiological studies. A BMI of 25 - 30 for men and 27 - 30 for women is considered moderate obesity. A BMI of 30 -40 is considered massive obesity, and a BMI greater than 40 is classified as morbid obesity.