Body mass index Quetelet index. How to determine your body type? The best indicator of body fat ratio

The same number on the scales can have different meaning. 80 kg with a height of 190 cm is the norm. But the same 80 kg at 160 cm is already too much, especially for a woman. So focusing on kilograms alone is not enough. Ideally, a person's height, gender, age and lifestyle should be taken into account. In this regard, to determine the norm and pathologies, they use such a concept as BMI.

What it is

BMI is an abbreviation for body mass index. In English it sounds like Body Mass Index (BMI). This is a parameter that reflects the degree to which a person’s weight and height correspond. Allows you to objectively assess whether he has overweight, whether he is suffering from exhaustion, or whether everything is normal. Most often used in two cases.

Secondly, calculating BMI is necessary in order to control your figure, correct it and, if it deviates from the norm, take appropriate measures.

Generally accepted formula

Now the BMI formula is officially used, developed in the middle of the 19th century by Adolphe Quetelet, a sociologist and statistician from Belgium. It takes into account only two parameters - height and weight, which does not make it ideal for identifying excess or missing kilograms. And yet, for many decades it has been used in medicine.

The Quetelet calculation formula looks like this:

• m (weight) = 80 kg;
• h (height) = 1.6 m;
• square meters: 1.6 x 1.6 = 2.56;
• I = 80 / 2.56 = 31.25.

This completes the calculation of the body mass index: it is equal to 31.25. We remember this figure and compare it with normal indicators, according to the table below.

Norm and deviations

On the official WHO website there is a special table that shows both the BMI norm and deviations. Using it, we look for which category we fell into with our I = 31.25.

IN normal index We didn’t include body weight, and the table shows not just extra pounds, but first-degree obesity (an overview of obesity classifications can be found).

So calculating BMI and comparing the data obtained with the norm is not at all difficult. The problem is that the formula is already outdated, and the WHO table does not reflect all factors. This means that the results may not be entirely correct.

For adults

Since weight is influenced by gender and age factors, tables have appeared where you can see the norm and deviations from it separately for women and men, and even taking into account age. As experts note, here the data is more accurate and correct.

For men based on age

For women, taking into account age

Depends only on gender

Depends only on age

Anything below normal is underweight. This means that you urgently need to gain the missing kilograms. If the result exceeds the parameter indicated in the table by 5 units, you are overweight. If the difference is more than 5, you should contact qualified assistance, since we are most likely talking about .

For children

To calculate BMI for children, you will need the same formula, but the table, accordingly, will be different. In a child, metabolic processes proceed much faster, and energy costs are several times higher than in adults. Therefore it is necessary to mandatory use other standards.

For boys

For girls

The jumps from 7 to 9 years are explained by the body’s preparation for adolescence and puberty.

Regular determination of a child’s BMI allows parents to control his weight and promptly prevent both exhaustion and the appearance of extra pounds (about the features childhood obesity read).

Ideal weight calculation

You can find out your ideal body weight using various formulas that use different parameters for calculations.

General designation (R - height):

• Bornhart index: R in centimeters x (multiply) by chest circumference in centimeters / (divide) by 240;
• Breitman index: R in centimeters x 0.7 - 50 kg;
• Broca–Bruksht index: for women R in centimeters – 100 – (R in centimeters – 100) / 10; for men R in centimeters – 100 – (R in centimeters – 100) / 20;
• Davenport index: weight in grams / R in centimeters squared;
• Korovin index: you need to measure the thickness skin fold near the 3rd ribs (normal 1-1.5 cm) and at the level of the navel (normal 1.5-2 cm);
• Noorden index: R in centimeters x 420 / 1,000;
• Tatonya index: R in centimeters - (100 + (R in centimeters - 100) / 20).

There is also a small addition to the Broca-Bruckst formula: after the result obtained, you need to measure the volume of the wrist, and if it is less than 15 cm, subtract 10% from the ideal weight; at 15–18 cm we do not change anything, if more than 18, we increase ideal weight, obtained according to the formula, by 10%.

Using any formula, calculating your ideal body weight is easy. The main thing is to draw objective conclusions after comparing the results obtained with real numbers. If the difference in both directions (more/less) is more than 5 kg, then there are problems that are better to start solving immediately.

Important note!

We draw your attention to the fact that in different sources, data on the norm and deviations of BMI for men, women and children, taking into account age, may differ quite noticeably with the exception general table recommended by WHO. The fact is that the parameters are calculated according to different methods and formulas - this is where the difference within one comes from. In this regard, all parents are recommended to use the data for children only as a guide and, in case of doubt, be sure to consult a pediatrician without taking any independent measures.

BMI – body mass index– reflects the state of human health. This indicator depends on the body’s fat resources and can correspond to the norm, be excessive or deficient. Many people have a body mass index that is far from optimal. No wonder BMI appeared in medical records How key factor risk of morbidity and began to be taken into account in diagnosis.

What is your body mass index?

According to WHO, half of the people on the planet die today not from dangerous infections like in past eras. The main enemies of man are fast food, overeating, stress, “sedentary” work and “sofa” leisure.

A whole generation of people has grown up suffering from obesity and doomed to type 2 diabetes, cardiovascular diseases, osteochondrosis and many others dangerous illnesses. The asymptomatic period of these pathologies can drag on for years, during which the body’s strength will slowly but surely be undermined. An increased body mass index will warn about the destructive activity of a latent disease.

In turn, a lowered BMI will signal another deviation from the norm - painful exhaustion of a person. This condition should also cause concern. An organism with insufficient fat deposits is not able to cope with its functions normally and resist diseases. Deficiency of adipose tissue may be a sign diabetes mellitus Type 1, osteoporosis, digestive disorders, breathing or mental problems.

In any case, your body mass index will allow you to come to your senses in time and begin to restore your physical shape. Of course, on the path to perfection you will need to pull yourself together, get rid of bad habits, sacrifice destructive addictions. However, the game is worth the effort, because the most valuable thing at stake is your life.

How to calculate body mass index?

To find out this indicator, you need to determine your weight (in kilograms) and measure your height (in meters). Then the number indicating the weight should be divided by the number obtained by squaring the digital expression of height. In other words, you need to use a formula that conveys the ratio of body weight to height:

BMI = M/P 2

(M – body weight, P – height in meters)

For example, your weight is 64 kg, height is 165 cm, or 1.65 m. We substitute your data into the formula and get: BMI = 64: (1.65 x 1.65) = 26.99. Now you can contact official medicine interpretation of BMI values:

• it does not take into account the ratio of muscle and fat mass, so BMI will not be able to adequately reflect the health status of a bodybuilder engaged in building muscle potential: if he calculates the body mass index using Quetelet’s formula, the results will show him in the company of loose fat people;
• These calculations are not suitable for older people: for 60-70 year old pensioners, being somewhat overweight is not considered dangerous to health, so the BMI range for them can be expanded from 22 to 26.

If you are not an elderly person or a bodybuilder, then Quetelet’s formula will do a good job of assessing the balance of your parameters. The magnitude of the error in this case will not interfere with understanding whether you are normal or not.

It should be kept in mind that the medical community's understanding of normal BMI may change over time. This was already the case on the threshold of the third millennium, when the BMI recommended by doctors dropped from 27.8 to 25. But Israeli scientists have proven that a body mass index of 25-27 is optimal for men: with this index they are guaranteed the longest life expectancy.

How to calculate body mass index online?

Our online calculator will become your fast and accurate assistant in calculating your BMI. You don't have to manually multiply and divide. The automatic program of an electronic calculator will save you from this puzzle.

Its operating principle is simple and clear. You only need to take three steps:

1. Please indicate your gender (by physiological reasons BMI for women is usually lower than for men).
2. Note your height (in centimeters) and weight (in kilograms).
3. Enter the full number of your years in the appropriate field.

After filling out the entire calculator form, click the “Calculate” button. Having received data from you, the program will immediately display correct result with recommendations from experts.

You'll learn what to do if your index is less than optimal or begins to drift away from it. Even if you still have a normal BMI, you should not neglect the wishes outlined here. Then you will not have health problems in the future.

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Our online Quetelet body mass index calculator allows you to determine for free the weight according to the height of an adult. BMI shows how much mass 1 meter of body area contains. The calculation formula was developed by the Belgian sociologist Adolphe Quetelet in 1869.

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YOUR BODY MASS INDEX

(BMI) shows whether your weight is medically normal.

The BMI indicator is used world organization health care for an approximate assessment of the normal body weight of a person. There are no exact criteria.

This value does not take into account the characteristics of age categories, so calculating BMI is only suitable for non-growing people 17-60 years old.

And in some cases, assessing physique using Quetelet’s formula is useless. For example, the body mass index of a professional athlete will be higher than normal due to developed muscles.

To ensure availability excess weight at the same time with online calculator body mass index is carried out.

How to find out the mass index

Body mass index can be calculated independently using the formula. When evaluating the results, remember that these specifications are approximate and do not represent medical diagnosis. If your BMI differs from the norm, do not rush to condemn yourself as “obese” or “.”

Discuss concerns about excess weight with your dietitian. Age, gender and lifestyle influence the predominance of fat or muscle in the body. It is likely that the result obtained is the norm for you.

Calculation of BMI using the formula is designed taking into account a person’s weight and height: BMI = Weight kg/height m2

In addition to Quetelet’s formula, you can determine whether body weight corresponds to the norm using other indices:

• You can calculate Broca's Index with a height of 155 to 170 cm. The calculation is made using the formula: (height (cm) – 100) ± 10%.
• Calculation of weight norms according to the Breitman index: height (cm) multiplied by 0.7 - 50 kg.
• The Bernhard index is calculated as follows: height (cm) multiplied by the circumference index chest(cm) and divide by 240.
• The Davenport index can be calculated using the formula: mass (g)/height (cm2). High result(greater than 3.0) means presence overweight.
• Calculation of the Oder index: multiply the distance from the parietal zone to the symphysis (cm) by 2 - 100.
• You can find the value of the Noorden index using the formula: height (cm) multiplied by 420 divided by 1000.
• Calculation of the Tatonya index: height (cm) – (100+(height (cm)-100)/20).

How to calculate BMI results

When you calculate the index and get the result, compare it with the indicators in the table.

Calculating BMI is conventionally divided into 3 ranges: underweight, normal and overweight, each of which includes several stages of body composition assessment.

• BMI less than 16– severe lack of weight, you need to consult a doctor. Most likely, the doctor will diagnose anorexia and prescribe a course of enhanced nutrition and psychotherapy. Anorexia is a disorder eating behavior, leads to exhaustion of the body, and death is possible.
• BMI less than 18.5– slight lack of weight. You need to eat more and include more fats in your diet. It’s better to contact a nutritionist to draw up a therapeutic program.
• BMI 18.5-24.9– normal weight. Maintain the average of this range, try not to go beyond the limits, this way you will save slim figure without signs of thinness or obesity.
• BMI 25-29.9– an indicator of excess weight. Obesity is far from being achieved; body weight can be reduced with exercise and healthy eating. Eliminate sugar from your diet and move more.
• BMI 30-34.9– . Consult a nutritionist, there is a risk of developing cardiovascular disease, atherosclerosis and diabetes.
• BMI 35-39.9– 2nd degree obesity. Consult a nutritionist, lose weight urgently, there is a chance of developing diseases associated with overweight, increases 3 times.
• BMI over 40– 3rd degree obesity. Excess weight threatens your life, consult a doctor. Use diets and other methods of losing weight only under the supervision of a specialist.

BMI tables based on age and gender

Interpretation of the Quetelet mass index is indicative. The calculation results for men and women, children and adolescents need to be adjusted and clarified. Pay attention to the tables for decoding BMI taking into account age and gender.

For women

Body mass index for women can be calculated in a similar way, using Quetelet's formula. But correct interpretation of the results is important; age also affects the result obtained:

• 19 – underweight;
• 20-25 – within normal limits;
• 26-30 – excess;
• 31+ is a sign of obesity.

BMI tables are useless during pregnancy - the result will not correspond to the norm, even if you have an excellent physique.

Men

A too low or high body mass index for men causes a six-month deferment from military service. When examined at the military registration and enlistment office, the correct calculation of BMI will determine the fate of the conscript. What mark will the doctor give - fit or not?

• 18 – underweight;
• 18.5-23.8 – within normal limits;
• 23,9-28,5 – overweight bodies;
• 29+ is a sign of obesity.

For athletes

Calculating the index using classical formula, do not take into account that one type of tissue predominates in the body: muscle or fat. At the athlete muscle mass more, so BMI is always high. Professional athletes use other norm indices.

For example, to calculate body proportions, divide your waist size by your hip size. Male norm– coefficient 1, women’s – 0.85.

For children and teenagers

Children's bodies grow and change, so the adult BMI formula is not suitable for children. Weight standards for children and adolescents are different. Calculations must be carried out taking into account age category and the gender of the child.

To determine the BMI of a child or adolescent, centile tables are used.

Centile table for determining BMI in girls under 10 years of age:

Centile table for determining BMI in boys under 10 years of age:

Each column of the centile table shows the normal limits in percentages or centiles. average value characterizes normal weight healthy child. The normal limits correspond to the range of 25-50-75%. Adjacent intervals respectively mean: 10-25% - below and 75-90% - above the average.

Centile table for determining BMI in teenage girls:

Centile table for determining BMI in teenage boys:

Age	Centiles
1 year
2 years
3 years
4 years
5 years
6 years
7 years
8 years
9 years
10 years
11 years
12 years
13 years
14 years
15 years
16 years
17 years
18 years
19 years

Centile values ​​of the Quetelet II index (body mass index). Girls.

Age	Centiles
1 year
2 years
3 years
4 years
5 years
6 years
7 years
8 years
9 years
10 years
11 years
12 years
13 years
14 years
15 years
16 years
17 years
18 years
19 years

The conclusion about the nutritional status based on the Quetelet-II index is made similarly to the general approaches using the nonparametric method. When determining the index in the zone from the 25th to the 75th centile, “sufficient” nutrition of the child is stated. A “low” (“very low”) nutritional status is defined as a body mass index score below the 10th (3rd) centile, respectively, and a “high” (“very high”) nutritional status is defined as a BMI score below the 10th (3rd) centile, respectively. above the 90th (97th) centile, respectively. With index values ​​corresponding to 10–15 or 75–90 centile intervals, we can speak of a “borderline” nutritional state (below or above average), requiring close dynamic monitoring by a doctor.

ASSESSMENT OF THE LEVEL OF BIOLOGICAL MATURITY

Individual fluctuations in the processes of growth and development served as the basis for the introduction of such a concept as biological age. The concept of biological age has great importance, since in many cases grouping by degree of development is important. The main criteria of biological age are: 1) maturity, assessed by the degree of development of secondary sexual characteristics; 2) skeletal maturity (the order and timing of skeletal ossification); 3) dental maturity (timing of eruption of milk and permanent teeth).

ASSESSMENT OF BONE TISSUE MATURITY

A generally accepted and reliable criterion for the degree of biological development both in prenatal life (from the 4-5th month of intrauterine development) and in all subsequent periods of postnatal ontogenesis is the so-called “bone age” (bone skeletal maturity). Its main indicator is the stage of skeletal ossification, determined radiographically by the number and size of epiphyseal ossification centers characteristic of a given chronological age, as well as the timing of synostosis (fusion of the epiphyses with the metaphyses).

The processes of ossification of the fetal skeleton begin approximately from the 5th month of intrauterine development. A healthy full-term newborn has an ossified distal epiphysis. tibia, and the proximal epiphysis of the fibula.

The appearance and development of ossification centers occurs in healthy children in a strictly defined sequence. At each age, the skeleton has a specific x-ray picture corresponding to a certain stage of maturation. Bone age determines the age at which, on average, there is a given stage of skeletal maturation and a given specific x-ray picture.

Determination of bone age is based on evaluation of a radiograph of the hand and wrist joint. The number and size of epiphyseal growth zones are assessed; the sequence of their appearance; bone size, density and shape; degree of closure of epiphyseal growth zones. Assessment of skeletal maturation is carried out by the method of Greulich and Pyle (1959) and the method of Tanner and Whitehouse (1975). The first method is based on a comparative assessment of a radiograph of the child’s left hand with the standards of the Radiographic Atlas of Skeletal Development of the Hand and Wrist, obtained during examination of healthy children of both sexes. (Rice.). The Tanner, Whitehouse method is based on the exact measurement of each bone and its expression in a numerical coefficient; the sum of these coefficients gives an indicator of bone maturation as a whole for the hand and wrist.

Timing of ossification of the skeleton of the hand and distal forearm

in children and adolescents (Zhukovsky M.A., 1980)

Bones and ossification centers	Average time of ossification
	boys
Carpal bones
Capitate
Uncinate
Triangular
Lunar	3 years 6 months	2 years 10 months
Polygonal	5 years 6 months	3 years 6 months
Trapezoidal	5 years 9 months	3 years 7 months
Scaphoid	5 years 6 months	4 years 3 months
pisiform		10 years 6 months
Metacarpal bones
Epiphysis of the second metacarpal bone	1 year 6 months
Epiphysis of the third metacarpal bone	1 year 8 months		1 year 1 month
Epiphysis IV metacarpal bone	1 year 11 months		1 year 3 months
Epiphysis of the fifth metacarpal bone	2 years 2 months		1 year 4 months
Epiphysis of the first metacarpal bone	2 years 6 months		1 year 6 months
Phalanges of fingers (epiphyses)
I Phalanx of the third finger	1 year 4 months
I Phalanx of the second finger	1 year 4 months
I Phalanx of the fourth finger	1 year 5 months
II Phalanx of the first finger	1 year 7 months
I Phalanx of the fifth finger	1 year 9 months		1 year 2 months
II Phalanx of the third finger			1 year 3 months
II Phalanx of the fourth finger			1 year 3 months
II Phalanx of the second finger	2 years 2 months		1 year 4 months
III Phalanx of the third finger	2 years 4 months		1 year 6 months
III Phalanx of the fourth finger	2 years 4 months		1 year 6 months
I Phalanx of the first finger	2 years 8 months		1 year 8 months
III Phalanx of the fifth finger	3 years 1 month		1 year 11 months
III Phalanx of the second finger	3 years 1 month		1 year 11 months
II Phalanx of the fifth finger	3 years 3 months		1 year 10 months
Sesamoid bone	13 years 6 months		11 years 6 months
Bones of the forearm
Distal epiphysis radius
Distal epiphysis of the ulna

Note: standard deviations of “bone age” from chronological are for children under one year old – 2 months; in the second year – 4 months; by 7 years – 7 months; over 7 years – 12-15 months.

ASSESSMENT OF THE LEVEL OF BIOLOGICAL MATURITY BY THE DATE OF ERUPTATION OF PERMANENT TEETH

The formation of teeth begins towards the end of the second, and their calcification begins from the 7th month of intrauterine life (mainly milk). Shortly before birth, calcification begins in the rudiments of those permanent teeth, which will erupt first. This process is finally completed by the age of 18-25.

Since the timing and sequence of milk production permanent dentition in children are sufficiently defined (Table), they are widely used in determining “dental age”, which is established by counting the number of erupted teeth and comparing it with standard age norms.

Milk teeth erupt at 6 months. Up to 2-2.5 years and at this stage of postnatal ontogenesis can serve as an indicator of physiological maturity.

Timing of baby teeth eruption

Age (in months)	Dental formula

Time of eruption of permanent teeth

There are two periods in primary dentition. The first lasts from the beginning of its formation to 3-3.5 years. During this period, the teeth are closely spaced without gaps between them, tooth wear is invisible, the bite is orthognathic due to insufficient growth and pulling forward of the lower jaw. The second period (from 3.5 to 6 years) is characterized by the appearance of physiological gaps between the teeth (diastema or trema), significant wear of the teeth and the transition of the bite from orthognathic to straight.

The change of primary teeth to permanent ones (the period of mixed dentition) characterizes the biological age in the range from 6-13 years. A correlation, although not very large, of dental age with skeletal development and the level of puberty has been revealed.

Teething occurs correctly when symmetrical teeth appear in pairs a certain sequence and within the appropriate time frame (table).

Calculation of Quetelet body mass index will help you determine how optimal your weight. This method received worldwide recognition among nutritionists and specialists in the field sports medicine, so you definitely can’t go wrong using it. After all, if body mass above normal, then the body cannot function normally, and if below normal, then it is likely to develop dystrophic processes. In both cases, you risk your health. So how calculate Quetelet body mass index? Everything is very simple!

Body Mass Index Calculation

For calculation of the Quetelet index divide your weight in kg by your height in meters squared.

Formula It has next view: BMI = m/h2

m – weight in kg, h – height in meters, BMI – Quetelet index.

We get what we are looking for body mass index, the meaning of which will be considered below.

Quetelet body mass index less than 15

This is a clear disadvantage weight, most likely dystrophy. There can be many reasons for a lack of muscle mass; in any case, this is already a reason to introduce increased nutrition or even consult a doctor; it is likely that you have a disease that prevents you from gaining muscle mass.

Quetelet body mass index from 15 to 20

a lack of weight, which is not so critical. Most often this body mass index people may have an asthenic body type or have an accelerated metabolism. Athletes (gymnasts, marathon runners, etc.) may also have this indicator. It is recommended to increase portion sizes or caloric content of food.

Quetelet body mass index from 20 to 25

Quetelet body mass index from 25 to 30

Excess weight. The reasons for falling out of the norm may be insufficient physical exercise, discrepancy between calorie intake and your energy expenditure, some diseases. Also elevated body mass index occurs in people with heavy bones and big amount muscle mass. In any case, there is already a health risk.

Quetelet body mass index over 30

Obesity. Very big problems With weight, and the body’s condition is close to critical. It is recommended to immediately consult a nutritionist, go in for fitness, and maybe visit a psychologist. If you don't take action active actions with this indicator body mass index, then diseases of the cardiovascular, respiratory, and endocrine systems are inevitable.

Quetelet body mass index over 40

Morbid obesity. Characterized by the presence of diseases of body systems and individual organs. This condition is critical and poses a danger not only to human health, but also to human life. It is necessary to urgently consult a doctor and receive treatment in a hospital.

By the way, before you sound the alarm and go on a strict diet, decide what you need. Do you want to shape your figure or get rid of extra pounds? Then you need to take into account the distribution of fat in various parts bodies. Try dividing your waist size (cm) by your hip size (cm). A critical indicator of more than 0.8 - excess belly fat can cause more dangerous consequences than on the hips. If the indicator is less than 0.8, then you are fine!