To determine the correct ratio of body mass index, one indicator of weight is not enough. This can be explained as follows. For example, with a height of 180 cm, a weight of 70 kg is considered normal, the same mass with a height of 160 cm already exceeds the norm. As a rule, several indicators are taken into account in the calculation at once. To denote the norm or deviations from it, use the concept of BMI (body mass index).
Description
Experts interpret this term as follows.
The body mass index or Body Mass Index is a value that reflects the degree of correlation of height and weight of a person. Thanks to a simple calculation, this indicator makes it possible to objectively assess whether a person is obese, anorexic, or everything is within normal limits. Most often, the calculation is made in two cases:
- If you suspect obesity or if eating disorders are detected, the attending physician may recommend the determination of BMI in order to make a more accurate diagnosis and prescribe effective treatment.
- Also, calculating the body mass index is necessary to control the figure, adjust eating habits and adopt appropriate methods for normalizing indicators.
Formula
BMI is calculated according to a formula developed in the mid-19th century by statistician and sociologist of Belgian origin Adolf Ketle. When calculating, only two indicators are taken into account: weight and height. Some skeptics consider it not the most accurate for determining the normal mass or deviation from it. However, physicians around the world take it into account.
The formula for determining the body mass index looks like this:
I = m ÷ h2
Accordingly, the index is equal to the ratio of weight to height squared (expressed in meters). The resulting indicator makes it possible to determine whether the mass is within normal limits.
Norm and deviations
Each person can independently calculate this value, and find the result in a special table approved by WHO. It not only shows excess or underweight, but also the stage of obesity or exhaustion. Nevertheless, some experts consider it obsolete, arguing that the norm of a man’s body mass index should be higher than that of a woman. The same goes for age. The older the person, the higher the rate should be.
For familiarization, we present the BMI table below.
Body Mass Index Obesity
Obesity is called the problem of the XXI century. It is caused not just by overeating. This is a chronic form of the disease that causes metabolic disorders.
The corresponding indicator is calculated according to the Ketle formula, and the result gives you the opportunity to find out how many kilograms a person needs to lose in order to get normal indicators.
Each degree of obesity according to body mass index is characterized by the following features:
- I degree of obesity. People with this indicator, as a rule, do not suffer from serious pathologies caused by excess weight. Most often they are limited to complaints about an ugly figure.
- II degree of obesity. Persons in this group begin to feel the problem of being overweight. Shortness of breath, palpitations, sleep disturbances, or insomnia appear. This degree of obesity is not considered neglected. With the right and timely approach to the disease, you can quickly restore shape and improve your health.
- III degree of obesity. People in this category are fully aware of the problem of being overweight. Even with a little physical exertion, fatigue, a desire to lie down, apathy and weakness appear. Often there are attacks of tachycardia, all organs experience an additional load, which subsequently leads to pathologies in their functioning.
- IV degree of obesity. An advanced form of the disease. In order to achieve normal indicators, a person will have to work hard for a long time, observing all the instructions of a doctor, trainer and nutritionist. People with this degree of obesity in terms of body mass index experience many health problems caused by being overweight. It is difficult for them to move around and independently perform basic hygiene procedures. The body does not cope, organs gradually begin to fail. If you do not take appropriate measures, life expectancy is sharply reduced.
For children
The calculation of the body mass index for children is carried out according to the standard formula, but the indicator is calculated according to another table.
The metabolic process in a child proceeds in an accelerated mode. In connection with an active lifestyle, to maintain tonus, children need much more energy, and hence healthy food, than an adult. Therefore, when calculating, they rely on other normative indicators.
In addition to age, the table takes into account the gender of the child. If you carefully study the data, you can see that at the age of 7 to 9 years, differences in values are observed. This is due to the preparation of a growing organism for a transitional age and puberty. The body mass index table for children is presented below.
It is enough to measure a child’s BMI twice a year to take timely measures in case excess weight appears or exhaustion is observed. In both situations, the health effects can be dire.
For adults
Since modern science considers the calculation using the Ketle formula to be obsolete, tables have been developed that allow you to calculate the body mass index taking into account the age and gender of the patient. According to experts, the indicator calculated in this way allows you to more accurately determine the extent of a possible problem.
According to the already known formula, BMI is calculated, and then the result is found in the table according to the sex and age of the person. A table with the corresponding values is presented below.
If the body mass index is normal, then nothing needs to be done. A coefficient below the standard means underweight. Accordingly, it is necessary to dial it, and not reset it. If the result is 5 units higher in the table, the person is overweight. If the indicator exceeds 5 units, the person is obese and he needs to start taking appropriate measures as soon as possible.
How to calculate the ideal weight?
You can individually calculate your suitable weight using one of several formulas. For each of them, the general designation R is used - growth in centimeters:
- Borngart's formula: R is multiplied by the chest circumference in cm and divided by 240.
- Breitman formula: R is multiplied by 0.7 and subtracted by 50.
- The Brock-Brookst Formula For women: R minus 100 and minus (R minus 100) divided by 10. For men: minus 100 and minus (R minus 100) divided by 20. After receiving the result, measure the thickness of the wrist. If it is less than 15.5 cm, 10% should be subtracted from the ideal weight. If the wrist is from 15 to 18 cm, the result does not change, if more than 18 cm, then 10% is added to the mass.
- Davenport formula: weight in grams divided by R squared.
- The formula of Korovin. Measure the thickness of the crease at the navel - the norm is up to 2 cm and the thickness of the crease at the rib - the norm is 1 - 1.5 cm.
- Noordon's formula: R is multiplied by 420 and divided by 1000.
When calculating the body mass index according to the Brock-Brooksht formula, it is necessary to carry out calculations to the end, despite their cumbersomeness.
Dependence of BMI and the appearance of diseases
An increase in this indicator is associated with an increased risk of cancer, including esophageal adenocarcinoma or cardia.
According to some reports, life expectancy also depends on BMI. In America, a study was conducted in the late 90s that involved men between the ages of fifty and seventy. According to the results of the experiment, experts concluded that people with a body mass index of 26 lived significantly longer than the rest. However, by 2009, a quarter of the subjects were gone. Based on this, the study was found to be inaccurate. It was concluded that the determining factors of life expectancy are the patient’s personal data, lifestyle and other components.
BMI and the army
In Russia, when passing a medical examination for service in the armed forces, the index value is also taken into account.
If the indicator is higher or lower than normal, the young man is once given a delay of six months. During this time, he must regularly undergo an examination in the clinic, where his weight and state of health are recorded. If during the observation no serious diseases or pathologies were revealed, and the mass remained the same, a person is not drafted into the army.
Different sources may indicate unequal rates of body mass index. Relying on data should be indicative or verify it with several information resources.