Question

What mean “body composition’? Briefly describe the assessment methods for determining a person’s body composition

Answer 1

Body composition is a method of describing what the body is made of which includes fat, protein, minerals and body water. Body composition analysis can accurately show changes in fat mass, muscle mass, and body fat percentage. Obesity in children and adults has highlighted the importance of understanding body fat levels for short-term and long-term health.

The most common assessments are anthropometric and include weight, stature, abdominal circumference, and skin fold measurements. More complex methods include bioelectrical impedance, dual-energy X-ray absorptiometry, body density, and total body water estimates

Anthropometric measurements are the most basic method of assessing body composition. Anthropometric measurements describe body mass, size, shape, and level of fatness.

Bone mineral density (BMD -The most accurate estimation of body composition is derived from body density by means of the equation of fractional densities which states that the overall density of a mixture containing more than one substance with a different density can be calculated if the proportion and density of each component substance is known Dual-energy X-ray absorptiometry is a means of measuring bone mineral density (BMD) using spectral imaging.

Air displacement plethysmography or ADP - Individual sits inside small chamber. Computerized pressure sensors determine the amount of air displaced by the person .Body volume is calculated by subtracting the air volume with the person inside the chamber from the volume of the empty chamber .Body density and percent body fat are then calculated.

Bioelectrical impedance analysis (BIA) is a commonly used method for estimating body composition, in particular body fat and muscle mass. In BIA, a weak electric current flows through the body and the voltage is measured in order to calculate impedance (resistance) of the body. Most of our body water is stored in our muscle. Therefore,

Body Volume Indicator (BVI) is a technique used for measuring body shape. Initially, BVI technology employed white light scanning machines to measure an individuals body shape. Recent technological advances in 3D measurement have enabled BVI to be calculated using images taken on a smartphone.

Skin fold method is by using gun style calipers to measure the thickness of subcutaneous fat in multiple places on the body. This includes the abdominal area, the subscapular region, arms, buttocks and thighs. These measurements are then used to estimate total body fat.

Ultrasound

Ultrasound has the advantage of being able to also directly measure muscle thickness and quantify intramuscular fat circumferences.

Mid arm circumference Assessment of somatic (skeletal) protein is typically determined by simple measurements and calculations including mid arm circumference (MAC).

Waist to Hip Ratio

Indication of the pattern of body fat distribution The WHO states that abdominal obesity is defined as a waist-hip ratio above 0.90 for males and above 0.85 for females helps to measuring the density of the athlete's body

Total Body Water

Total body water is easy to measure because it does not require undressing or any real physical participation. Water is the most abundant molecule in the body, and TBW volume is measured by isotope dilution.