Body Fat Monitors

Human body consists of two types of fats, the essential fats and the body fats. Essential fats are responsible for body metabolism and consist of fats stored in the lungs, heart, kidneys, liver, spleen, intestines, bone marrow, muscles, and in parts of the central nervous system. Body fats or storage fats are loose connective tissue (adipose tissue), which store energy in the form of fats. In fact, storage fats play an important role in protecting the internal organs of the body and in supplying energy at times of need. However, too much accumulation of body fats leads to a condition called obesity.

A person’s body weight is defined as a measure of the total lean body mass (mass of organ, bone, muscle and water) and fat mass. The recommended body weight for a person depends upon his/her height. The general tool used for analyzing a person’s healthy body weight based on his/her height is known as body mass index (BMI). A person having a BMI of 25 kg/m² or higher is considered to be overweight. Similarly, a person is called obese, if his/her BMI is 30 kg/m² or higher. There are various heath complications for an obese person.

Body Fat Monitors

Considering the fitness and well-being of a person, the body fat percentage is more important than the overall weight. Monitoring of body fat is an important way for determining the percentage body fat. Certain techniques are used for estimating percentage of body fat. Let’s see some of the commonly used body fat monitors.

Bioelectrical Impedance Analysis (BIA): BIA is a commonly used technique for calculating the percentage of body fat by analyzing the electrical resistance, generated due to fat mass of the body. These monitors are easy to operate and are available for home use. It is a fact that the conductivity or impedance of various tissues of the body varies and this forms the principle for this technique. A very low voltage electric signal is passed to the body and measures the impedance of the lean tissues and fat tissues. Since lean tissues have more water content, the conductivity is more as compared to fat tissues that have less water content. BIA devices use the data and find out the body fat percentage. The inaccuracy percentage of BIA is found out to be +/-3%.

Near Infrared Interactance (NIR): NIR is a method of analyzing body fat based on the principle of light absorption and infrared spectroscopy (practice of measuring the emission and absorption of different wavelengths of infrared light). NIR uses colors for different body surfaces, such as biceps and hips along with a computerized spectrophotometer that analyzes the emitted infrared light. Values of reflected light for muscles and fats are different and are taken into consideration in the measurement of body fat. Although this method is safe, fast and convenient, its use is limited because of less accuracy.

Dual Energy X-ray Absorptiometry (DEXA): DEXA is the most popularly used scanning tool for determining bone density, which can also be used in assessing total body composition and fat distribution. The principle used is based on the fact that density of a bone is directly proportional to the amount of photon energy absorbed by the particular bone, which is being studied. This type of monitors uses two radiations of different wavelengths at a set frequency to measure bone density, lean body mass and fat mass. DEXA is a quick, accurate and reliable tool, however, the disadvantage is that DEXA machines are very costly and are not affordable for home use.

Calipers (Skinfold Measurements): Calipers are used for analyzing body fat by measuring the skinfold thickness. In this method, usually hand-held calipers are used for estimating the subcutaneous tissue. The body sites for skinfold measurement vary for men and women. For example, a three-site skinfold in case of men measures chest, abdomen and thigh, whereas tricep, suprailiac and thigh are measured for women. Calipers are an easy and inexpensive way of estimating body fat. However, it is difficult to measure the skinfold of an obese person. The accuracy of this tool depends upon the quality of the calipers and the skill of the technician.

At present, body fat monitors are becoming more popular than the traditional weighing machines. Other body fat monitors include Hydrodensitometry Weighing (underwater weighing to determine body density, that can be used in estimating body fat), Magnetic Resonance Imaging (scanning procedure to analyze lean body mass, bone and body fat) and Total Body Electrical Conductivity (technique that determines lean body mass and fat based on their conductivity). These monitors are very useful while losing weight in knowing whether the lost weight comes from the lean body mass or the fat mass.