Body composition refers to the percentage of body weight that is fat and is based on the assumption that the body weight can be divided into fat mass and lean body mass. Lean body mass is assumed to include muscles, bones, organs, lean body mass, etc. The recommendation for healthy percent body fat in men is 12-17 percent and in women is 18-22 percent.
The scientific measurement and evaluation of body composition permit accurate quantification of the major structural composition of the body-fat, muscle and bone. This knowledge is crucial to the successful completion of any fitness regime. Although height-weight tables are still used to assess the weight status of the individuals, based on age and body frame size, such tables do not permit an assessment of the relative composition of the body. A person may weigh much more than the average weight for height standards, yet still be ‘underfat’ in terms of the body’s total quantity of fat. The so-called ‘excess weight’ could simply be additional muscle mass.
Optimal body weights for health and competition should be determined individually and are determined by age, gender, physical activity or sport, somatotype, genetics and individual variation. Health risks increase for those who are more than 20 percent over optimal weight. Health risks also increase as proportion of body fat increases. The importance of maintaining a healthy body composition extends beyond the aesthetic and athletic goals. Body composition is a preferred measure of health and fitness over body weight alone.
Weight for height charts is useful for tracking growth velocity. However, these charts do not provide information on body composition and the distribution of lean body mass and adipose tissue. The overweight person is not necessarily fat and the underweight person is not necessarily lean. Those involved in power sports appear to be overweight according to these charts but actually, have a high lean-to-fat ratio.
Most athletes require a high strength-to-weight ratio to achieve optimal athletic performance. Adipose tissue adds to body weight affecting strength. Percent body fat values for athletes range from 5-12 percent in men and 10-12 percent in women. Body fat levels below 4 and 10 percent for men and women respectively are possible indicators of eating disorder.