The same number on the scale can have different meanings. 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 it’s not enough to focus on kilograms alone. Ideally, you need to take into account the height, gender, age and lifestyle of a person. In this regard, to determine the norm and pathologies, they use such a concept as BMI.
What it is
BMI is short for body mass index. In English, it sounds like the Body Mass Index (BMI). This is a parameter that reflects the degree of correspondence between the weight and height of a person. Allows you to objectively assess whether he has overweight whether he suffers from exhaustion, or whether everything is normal with him. Most often used in two cases.
Secondly, BMI calculation is necessary in order to control your figure, correct it and, in case of deviation from the norm, take appropriate measures.
Common Formula
Now the BMI formula is officially used, developed back in the middle of the 19th century by Adolf 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 extra or missing kilograms to the norm. Nevertheless, it has been used in medicine for many decades.
The formula for calculating Quetelet looks like this:
- m (weight) = 80 kg;
- h (height) = 1.6 m;
- we square the meters: 1.6 x 1.6 \u003d 2.56;
- I \u003d 80 / 2.56 \u003d 31.25.
This completes the calculation of the body mass index: it is 31.25. We remember this figure and compare it with normal indicators, according to the table below.
Norm and deviations
The WHO official website has a special table that shows both the BMI norm and deviations. We are looking for which category we fell into with our I \u003d 31.25.
We didn’t get into the normal body mass index, and the table shows not just extra pounds, but obesity of the first degree (an overview of obesity classifications can be found).
So it’s not at all difficult to calculate BMI and compare the data obtained with the norm. The problem is that the formula is already outdated, and the table from WHO does not reflect all the factors. And this means that the results may not be entirely correct.
For adults
Since weight is influenced by gender and age factors, tables have appeared according to which you can see the norm and deviations from it separately for women and for men, and even taking into account age. According to experts, here the data is more accurate and correct.
For men according to age
For women according to age
Depending only on gender
Depending only on age
Anything below normal is underweight. So, you need to urgently 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 seek qualified help, as we are talking about, most likely.
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 imperative to use other standards.
For boys
For girls
Jumps from 7 to 9 years old are explained by the preparation of the body for adolescence and puberty.
Regular determination of BMI in a child allows parents to control his weight and timely prevent both exhaustion and the appearance of extra pounds (read about the features of childhood obesity).
Ideal weight calculation
You can find out your ideal body weight using various formulas that use different parameters for calculations.
General designation (R - height):
- Borngart index: R in centimeters x (multiply) by chest circumference in centimeters / (divide) by 240;
- Breitman index: R in centimeters x 0.7 - 50 kg;
- Brock-Brukst 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 of the skin fold near the 3rd rib (normal 1-1.5 cm) and at the level of the navel (normal 1.5-2 cm);
- Noorden index: R in centimeters x 420/1000;
- Tatonya index: R in centimeters - (100 + (R in centimeters - 100) / 20).
There is also a small addition to the Broca-Bruksta 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 the ideal weight obtained by 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 result with real numbers. If the difference in both directions (more/less) is more than 5 kg, then there are problems that it is 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, can differ quite noticeably, with the exception of the general table recommended by WHO. The fact is that the parameters are calculated according to different methods and formulas - hence the difference arises within the unit. In this regard, all parents are advised to use the data for children only indicatively and, in case of doubt, be sure to consult a pediatrician without taking any independent measures.
BMI is an abbreviation for English language Body Mass Index, which translates as " body mass index". BMI is the ratio of body weight to height, which determines that a person is insufficient, normal or overweight body.
BMI is one of the important methods for determining physical condition, but, unfortunately, it is not always enough. An important addition to the body mass index is the determination of the amount of fat in abdominal cavity- too much can mean dangerous abdominal obesity, even with a normal BMI. In addition, paradoxically, studies show that people with a slightly higher index tend to be healthier and live longer than those who have it in the normal range (have a "normal weight"). There is even speculation that perhaps the WHO threshold for overweight (25) is too low.
BMI calculation
The formula is very simple:
BMI = body weight in kilograms divided by height in meters squared.
For example, for a person with a height of 1.82 m and a weight of 76 kg, the BMI will be:
76 kg: (1.82 m)² = 76: (1.82 x 1.82) = 22.9
With the Body Mass Index Calculator, it is easy to determine the presence of fat in the body. Just enter your height in centimeters and weight in kilograms.
BMI calculator online
Body mass index (BMI)- a generally accepted indicator of the ratio of weight and height of a person - was first proposed by the Belgian mathematician Adolphe Quetelet in the middle of the 19th century. It is not difficult to calculate the body mass index - below you will find a simple formula for calculating BMI based on age. In our time, a close relationship has been revealed between the BMI indicator and a number of dangerous diseases (among which the most common are elevated blood cholesterol levels, heart attack, stroke, some cancers, lipid metabolism disorders, obesity). Depending on this or that degree of obesity (using the BMI indicator, which can be calculated and the degree of obesity can be determined from the table), it is necessary to choose the appropriate diet program or undergo a course of treatment after consulting a nutritionist.
Let's take a closer look at what other risk factors, in addition to the presence of one degree or another of obesity, can pose a danger to your health:
Hypertension ( high level blood pressure) reduced cholesterol (Lipoprotein Low Density high density lipoprotein); elevated cholesterol levels; elevated levels of neutral fats (triglycerides) in the blood, which is a direct consequence of obesity or very low physical activity.
The factors listed below are not directly related to BMI, but can indirectly affect the development of certain diseases. It should also be taken into account that the constitution of the body is due to heredity and cannot be adjusted:
Waist circumference 102 cm or more (for men)
Waist circumference 89 cm or more (for women)
Heart disease in one or more close relatives.
It is especially useful to know the body mass index for women. Thanks to the calculated BMI, you can adjust your chosen diet for weight loss and identify the problem of excess weight in time.
It should also be taken into account that even a slight weight loss (5-10%, if 1 or 2 degrees of obesity are detected) can significantly reduce the risk of developing diseases associated with overweight.
If your body mass index range is between 25kg/m2 - 29.9kg/m2, it is advisable to consult a nutritionist. It is possible that you will be advised to maintain your current weight (body constitution plays a key role here). However, we can safely say that in order to prevent weight gain and to reduce the likelihood of developing the above diseases, it is useful to lead an active lifestyle and eat in moderation.
Below you can calculate the body mass index using the formula and see the table "Degrees of obesity"
For example, the BMI for a girl who is 165 cm (1.65 m) tall and weighs 52 kg would be 19.1.
1.65² = 2.7225
52: 2.7225 = 19.1
MASS DEFICIENCY <18,50
Severe underweight<16,00
Underweight 16.00 - 18.49
NORM 18,50 - 24,99
Overweight >25.00
Preobesity 25.00 - 29.99
OBESITY >30,00
Obesity of the first degree 30.00 - 34.99
Obesity of the second degree 35.00 - 39.99
Obesity of the third degree >40.00
By the way, calculate your ideal body weight is also very easy: just multiply the square of your height in meters by the desired indicator within the norm. Let's say we take 19.7 as a guideline. Then, with a height of 165 cm, your weight should be 54 kg (1.65²x21≈54 kg).
As we age, our metabolism slows down and some other changes occur that affect BMI. Body mass index adjusted slightly for age.
Everything is very simple here: for the age of up to 24 years, the BMI norm is within 19-24, and then for every next ten years of life, the upper limit of the norm increases by one - up to 25 for the age of 25-34 years, to 26 for the age of 35-44 year, etc.
AGE| ACCEPTABLE BMI |
19 - 24
19 - 24
25 - 34
20 - 25
35 - 44
21 - 26
45 - 54
22 - 27
55 - 64
23 - 28
over 65 24 - 29
VIDEO MATERIALS:
/ body mass index
Body mass index (BMI)
You think that you are overweight - but is it? Assess your degree of completeness using a recognized international methodology. First of all, determine your body mass index (BMI).
The body mass index is a formula by which experts around the world estimate the ratio of an adult's body weight to his height. This indicator is very convenient, since in most people it is closely correlated with the content of adipose tissue. However, it is not suitable for weightlifters and some other athletes, pregnant and lactating women, and fragile elderly people. For children, there is a separate calculation method.
A high body mass index is associated with an increased risk of mortality from any cause, including diabetes, disease of cardio-vascular system, hypertension and arthritis (we will talk in more detail about diseases associated with overweight).
Calculating BMI
The calculation is very simple. BMI is equal to your weight in kilograms divided by the square of your height in meters:
| BMI= | Weight, kg) |
| Height (m) 2 |
Example: My BMI = 83.9: (1.84 x 1.84) = 24.78
Below is a table of already calculated BMIs for various height-to-weight ratios that will work for most people. If your parameters are not in the table, calculate your BMI using the formula above.
BODY MASS INDEX
Find your height, then in the corresponding column - the closest weight to you. On the same line in the far right column will be your approximate BMI.Height, m |
BMI |
||||||||
1,5 |
1,55 |
1,6 |
1,65 |
1,7 |
1,75 |
1,8 |
1,85 |
||
weight,
|
40 | 43 | 46 | 49 | 52 | 55 | 58 | 62 | 18 |
| 43 | 46 | 49 | 52 | 55 | 58 | 62 | 65 | 19 | |
| 45 | 48 | 51 | 54 | 58 | 61 | 65 | 68 | 20 | |
| 47 | 50 | 54 | 57 | 61 | 64 | 68 | 72 | 21 | |
| 50 | 53 | 56 | 60 | 64 | 67 | 71 | 75 | 22 | |
| 52 | 55 | 59 | 63 | 67 | 70 | 75 | 79 | 23 | |
| 54 | 57 | 61 | 65 | 69 | 73 | 78 | 82 | 24 | |
| 56 | 60 | 64 | 68 | 72 | 77 | 81 | 86 | 25 | |
| 63 | 67 | 72 | 76 | 81 | 86 | 91 | 96 | 28 | |
| 67 | 72 | 77 | 82 | 87 | 92 | 97 | 103 | 30 | |
| 79 | 84 | 90 | 95 | 101 | 107 | 113 | 120 | 35 | |
| 90 | 96 | 102 | 109 | 116 | 122 | 130 | 137 | 40 | |
Table comments
BMI below 18.5
BMI 18.5-24.99
BMI 25-29.99
BMI 30-34.99
BMI 35-40
BMI over 40
NOTE: Overweight and obesity can be determined by the fat content, for which you will need special equipment.
10 second test
Waist size is a reliable indicator of whether your weight is a health hazard. Measure your waist without pulling the measuring tape tight or loosening it too much. The waist is measured at the narrowest part of the torso, or approximately 2.5 cm above the navel. Record the measurement and evaluate by key:
Men
Waist circumference over 94 cm indicates
With a waist circumference over 102 cm
significant health risk
increases.
Women
Waist circumference over 80cm indicates
some health risk.
With a waist circumference of more than 88 cm, the risk to health increases significantly.
NOTE: Abdominal obesity can also be identified using waist/height and waist/hip ratios. However, they are more difficult to use and, as studies show, do not exceed the accuracy of the waist measurement test given here.
Talisman: Waist / Height Ratio
Waist/Hip Ratio
The last way to evaluate your figure is the ratio of waist to hips. Divide your waist by your hips to get your ratio.
For men, a ratio above 0.95, and for women above 0.80 indicates excess belly fat and increased health risks.