To determine the correct ratio of body mass index, one indicator of weight is not enough. It can be explained like this. For example, with a height of 180 cm, a weight of 70 kg is considered normal, the same weight with a height of 160 cm already exceeds the norm. As a rule, the calculation takes into account several indicators at once. To indicate the norm or deviations from it, use the concept of BMI (body mass index).
Description
Specialists decipher this term as follows.
Body mass index or Body Mass Index is a value that displays the degree of ratio 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 the normal range. Most often, the calculation is made in two cases:
- If obesity is suspected or if an eating disorder is detected, your doctor may recommend a BMI determination in order to make a more accurate diagnosis and prescribe an effectivetreatment.
- Also, the calculation of body mass index is necessary to control the figure, adjust eating habits and adopt appropriate methods for normalizing indicators.
Formula
The BMI is calculated using a formula developed in the mid-19th century by Belgian-born statistician and sociologist Adolphe Quetelet. When calculating, only two indicators are taken into account: weight and height. Some skeptics consider it not the most accurate for determining normal mass or deviation from it. However, it is she who is taken into account by doctors around the world.
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 the normal range.
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 malnutrition. However, some experts consider it outdated, arguing that the norm for a man's body mass index should be higher than that of a woman. The same applies to age. The older the person, the higher the score should be.
For reference, we present the BMI table below.
Degree of obesity by body mass index
Obesity is called the problem of the XXI century. It's not just caused by overeating. This is a chronic form of the disease that causesmetabolic disorder.
According to the Quetelet formula, the corresponding indicator is calculated, and the result obtained makes it possible to find out how many kilograms a person needs to lose in order to gain normal indicators.
Each degree of obesity in terms of 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 being overweight. Most often they are limited to complaints about an ugly figure.
- II degree of obesity. Individuals in this group begin to feel the problem of excess weight. There is shortness of breath, palpitations, sleep disturbances or insomnia. This degree of obesity is not considered advanced. With the right and timely approach to the disease, you can quickly restore shape and improve your he alth.
- III degree of obesity. People belonging to this category, fully feel the problem of excess weight. Even with a slight physical exertion, fatigue, a desire to lie down, apathy and weakness appear. Tachycardia attacks are often observed, all organs experience additional stress, which subsequently leads to pathologies in their functioning.
- IV degree of obesity. advanced form of the disease. To gain normal performance, a person will have to work long and hard, observing all the prescriptions of a doctor, trainer and nutritionist. People suffering from this degree of obesity in terms of body mass index experience many he alth problems caused by being overweight. Themit is difficult to move around and independently perform elementary hygiene procedures. The body can not cope, the organs gradually begin to fail. If the appropriate measures are not taken, life expectancy is drastically reduced.
For kids
The body mass index for children is calculated according to the standard formula, but the indicator is calculated according to a different table.
The process of metabolism in a child proceeds in an accelerated mode. In connection with an active lifestyle, to maintain tone, children need much more energy, and therefore he althy food, than an adult. Therefore, the calculations are based 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 there are differences in values between the ages of 7 and 9 years. This is due to the preparation of the growing body for the transitional age and puberty. The BMI table for children is shown below.
It is enough to measure the child's BMI twice a year for timely action in case of overweight or malnutrition. In both situations, the he alth consequences can be dire.
For adults
Because modern science considers the calculation of the Quetelet formula 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 allowsmore 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 gender and age of the person. The table with the corresponding values is shown below.
If the body mass index is normal, then nothing needs to be done. A coefficient below the standard means a lack of weight. Accordingly, it is necessary to dial it, and not reset it. If the result in accordance with the table above is 5 units, the person is overweight. If the indicator exceeds 5 units, the person is obese and 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 - height in centimeters:
Borngart's formula: R is multiplied by the circumference of the chest in cm and divided by 240
- Breitman's formula: R is multiplied by 0, 7 and subtracted by 50.
- Brock-Bruksta 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% must be subtracted from the ideal weight. If the wrist is from 15 to 18 cm, the result does not change, if it is more than 18 cm, then 10% is added to the mass.
- Davenport's formula: weight in grams divided by R squared.
- Korovin's formula. Measure the thickness of the foldat the navel - the norm is up to 2 cm and the thickness of the fold at the rib - the norm is 1 - 1.5 cm.
- Noordon formula: R is multiplied by 420 and divided by 1000.
When calculating the body mass index using the Broca-Brukst formula, it is imperative to carry out the calculations to the end, despite their cumbersomeness.
Relationship between BMI and occurrence of diseases
The increase in this indicator is interconnected with an increase in the risk of oncological diseases, including adenocarcinoma of the esophagus or cardia.
According to some reports, life expectancy also depends on BMI. In America, in the late 90s, a study was conducted in which men aged from fifty to seventy participated. According to the results of the experiment, experts concluded that people with a body mass index of 26 lived much longer than the rest. However, by 2009, a quarter of the subjects were gone. Based on this, the study was deemed inaccurate. It was concluded that the determining factors of life expectancy are the patient's personal data, lifestyle and other components.
BMI and Army
In Russia, when passing a medical examination for service in the armed forces, the value of the index is also taken into account.
If the indicator is above or below the norm, the young man is once given a delay of six months. During this time, he is obliged to regularly undergo an examination at the clinic, where his weight and state of he alth are recorded. If the observation revealed noserious diseases or pathologies, and the mass remains the same, a person is not drafted into the army.
Different sources may indicate unequal body mass index norms. You should rely on the data approximately or compare them with several information resources.
