The ideal body mass index is a value that allows you to determine the correctness of the ratio of the body weight of a person and his growth. Calculation of the body mass index of a person helps to assess whether there are variations in weight, underweight or excess.
The body mass index is the norm for women
The indices of body mass index were developed back in 1869 by the Belgian statistician and sociologist Adolf Ketele. To determine this indicator, the formula is proposed:
BMI (body mass index) = mass / height in square
That is, the body mass index is equal to the body mass divided by the square of the height taken in meters.
For example, with an increase of 160 cm and a weight of 55 kg, we get the following result 55 kg / 1.6х1.6 = 55 / 2.56 = 21.48.
The obtained results are interpreted in accordance with the following norms:
- 16-18.5: insufficient body weight;
- 18.5-25: ideal body weight;
- 25-30: initial signs of obesity ;
- 30-35: obesity of the first degree;
- 35-40: second degree obesity.
However, the normal body mass index is suitable only for adults and for those who do not engage in sports on a professional level. The normal weight of the body of athletes may be higher than in people who do not engage in sports, due to increased muscle mass.
Body mass index for women by age
When calculating the body mass index, you should take into account the age of a person. After all, with age, each person gradually gaining weight, and this is considered normal.
Norms of body mass index as a function of age (ideal index):
- 19-24 years: 19.5;
- 25-34 years: 23.2;
- 35-44 years: 23.4;
- 45-54 years: 25.2;
- after 55 years: 27.3.
Both shortages and excess weight are equally harmful to the body. Therefore, do not try to reach the minimum figures. At a low weight a person becomes susceptible to various diseases and loses activity.
In addition to the Ketele formula, there are other formulas that make it possible to calculate the body mass index. One of the most famous is the Broca index, used for women, whose growth is 155-170 centimeters. To determine the ideal body weight, it is necessary to subtract the number 100 from the growth of a person in centimeters, and then 15% for women and 10% for men.
Body mass indexes give only approximate results. They can be guided, but do not take them for absolute truth. The body mass index indices do not take into account some factors that also influence the available weight: the volume and weight of muscle mass, the amount of fat deposits, the ratio of fat and muscles.