Are you too thick, too thin, or of normal weight? The Body Mass Index (BMI) is often used as a guide to determine nutritional status. Find out how to calculate your personal BMI and what it says exactly here.
Body mass index
Body size and weight provide useful information about a person’s current nutritional status. These two body measurements are almost linearly related to each other in adults and form the basis of the Body Mass Index (BMI).
The body mass index (BMI) is calculated from the body weight (in kilograms or pounds) and divided by the square of the body size (in square meters or inches): BMI = weight [kg] / height [m^2].
Calculate your index here.
The “desirable” BMI also depends on age, so children’s BMI is not measured by these terms.
|over 64 years||24-29|
The BMI Division
BMI is used for the classification of overweight. The World Health Organization (WHO) has classified body weight in adults according to BMI. The following table is independent of gender and age:
|low mass weight||<16|
|low moderate weight||16.00-16.99|
|low light weight||17.00-18.49|
|Class I obesity||30.00-34.99|
|Class II obesity||35.00-39.99|
|Class III obesity||≥ 40|
Difficulties in determining BMI
However, there are some pitfalls in BMI. For one thing, it doesn’t distinguish between fat and lean mass: even with an increased BMI, malnutrition could still be present. For example, if muscle mass is massively reduced but fat mass increases at the same time.
Competitive athletes and bodybuilders who have a higher body weight due to their high muscle mass could also be wrongly classified as overweight with the help of BMI.
On the other hand, BMI cannot differentiate between fat mass and water. The accumulation of water in a person’s tissues increases body weight, which could lead to incorrect and excessive BMI.
Other anthropometric parameters
The determination of BMI alone is not sufficient to assess a person’s body composition. In addition, it is recommended to consult various anthropometric parameters.
This includes the body size, the body weight, the length of the arm, the muscle circumference of the upper arm, and the measurement of the thickness of the skin fold in various parts of the body.
Measurement of skin fold thickness
The skinfold thickness measurement measures the fat in the subcutaneous tissue, which constitutes approximately 50 percent of the reservoir fat, and is used to assess the amount of body fat.
Measurement of skin fold thickness is quick and easy to perform, but should be professionally performed by a physician.
Based on the sum of all measured skinfold thickness, the corresponding body fat content can now be read using a table. The precision of the results can be increased with an increasing number of recorded skin folds and the measurement made.
Arm Muscle Circumference
A rough estimate of muscle mass or fat can be made by measuring the arm muscle circumference. The circumference of the upper arm is measured at the midpoint between the shoulder joint and the elbow. It is believed that twice the thickness of the fat layer of the upper-middle arm corresponds to the skin fold of the triceps.