The BMI is the index most used to obtain a general assessment of one's body weight
The Body Mass Index (BMI) or Body Mass Index (BMI) is a parameter widely used to obtain a general assessment of one's body weight.
It relates the height to the weight of the subject with a simple mathematical formula.
It is obtained by dividing the weight in kg of the subject with the square of the height expressed in meters.
The result of this formula classifies the subject into an area of weight that can be: normal - underweight - overweight - medium grade obesity - high grade obesity.
| BMI | CONDITION |
| <16.5 | SERIOUS MAGREE |
| 16 to 18.49 | UNDERWEIGHT |
| 18.5-24, 99 | normal weight |
| 25 to 29.99 | OVERWEIGHT |
| 30 to 34.99 | CLASS I OBESITY (mild) |
| 35 to 39.99 | CLASS II OBESITY (average) |
| > 40 | OBESITYCLASSES III (serious) |
Calculate your BMI online
Example: If your weight is 80 kg and you are 185 cm tall, your BMI is:
80 / (1.85 x 1.85) = 23.4
Your body weight is in the "NORMOPESO" range
In depth:
Interpretation of BMI in children and adolescents;
BMI and body fat percentage;
Body mass index;
BMI and travel.
The optimal value of BMI
Statistical studies have shown that the BMI value associated with lower morbidity and mortality for all diseases for which overweight is a risk factor (cardiovascular disease, diabetes, hypertension, osteoarthritis, some neoplasms) is between 20 and 25.
IN PARTICULAR THE OPTIMAL VALUE OF BMI IS RESPECTIVELY:
- from 19 to 35 years: BMI = 22 (19-25)
- over 35 years: BMI = 24 (21-27)
The limits of BMI
BMI is a very useful index, fast to calculate and adaptable to most subjects.
However the BMI hides within itself great limitations especially when referred to athletes. This parameter, in fact, represents an approximate calculation since it does not take into account the type of physical constitution (slender, medium, robust) and the muscular masses of the subject.
A classic example is the one shown in the following image:
Both subjects are obese. In reality, Mario's body fat percentage is very low while Gianni's is high.
Having a BMI <25 is therefore a necessary condition, but not sufficient, to be able to define itself as "normal weight".
Having a BMI> 25 is therefore a necessary, but not sufficient, condition to be able to define yourself as "overweight".
The percentage of fat mass is the true indicator to determine the weight; it can be measured using various methods, among which the most widespread is plicometry.
To be sure, the fat mass can also be estimated from the BMI, but this calculation keeps all the limits just described for the evaluation of the body max index.
As regards the poor reliability of the BMI for very high (> 200 cm) or very low (<150 cm) individuals, a new, more precise formula has been recently proposed (see article: the new BMI)
