# Body mass index calculator

## What is BMI?

BMI is the abbreviation for Body Mass Index. It is a conditional value for the assessment of weight, which is characterized by the mass per square of the human body. The index allows you to determine the state of the human body: its insufficient or excessive weight. You can calculate BMI using a special formula that was invented by the Belgian mathematician Adolphe Quetelet more than 150 years ago.

The resulting data cannot be taken categorically and should be treated with caution, since the calculation takes into account only height and weight. Therefore, over time, several refinements to the formula were developed, which are applied depending on who the calculations are made for: for a man, woman, child or teenager. But only a doctor can correctly calculate BMI and give correct recommendations. Regardless of gender and age, a generalized table of BMI Quetelet has been developed, according to which it is possible to establish a weight deficit, its norm and the degree of obesity.

Body Mass Index (kg/m2) Classification
less than 18.5 Underweight
18.5 - 24.9 Normal weight
25 - 29.9 Overweight
30 - 34.9 Class I obese
35 - 39.9 Class II obese
40 upwards Class III obese

## Facts about overweight and obesity

Some of the recent global estimates from WHO are summarized below:

• In 2016, more than 1.9 billion adults over the age of 18 were overweight. Of these, over 650 million were obese.
• According to 2016 data, 39% of adults over 18 years old (39% of men and 40% of women) were overweight.
• In 2016, about 13% of the world’s adult population (11% of men and 15% of women) were obese.
• From 1975 to 2016, the number of obese people worldwide more than tripled.

It is estimated that in 2016, about 41 million children under the age of 5 were overweight or obese. Overweight and obesity, once thought to be common in high-income countries, are now becoming more prevalent in low- and middle-income countries, especially in cities. In Africa, the number of obese children under 5 years of age has grown by almost 50% since 2000. In 2016, almost half of overweight or obese children under 5 years of age lived in Asia.

In 2016, 340 million children and adolescents aged 5 to 19 were overweight or obese.

The prevalence of overweight and obesity among children and adolescents aged 5 to 19 has risen sharply from just 4% in 1975 to just over 18% in 2016. This increase is equally distributed among children and adolescents of both sexes: in 2016, 18% of girls and 19% of boys were overweight.

In 1975, just under 1% of children and adolescents aged 5 to 19 suffered from obesity, and in 2016 this number reached 124 million (6% of girls and 8% of boys).

In general, more people die from the effects of overweight and obesity worldwide than from the effects of abnormally low body weight. Obese people outnumber people underweight; this is the case in all regions except parts of sub-Saharan Africa and Asia.

## What are the most common health effects of being overweight and obese?

An elevated BMI is one of the main risk factors for noncommunicable diseases such as:

• cardiovascular disease (mainly heart disease and stroke), which was the leading cause of death in 2012;
• diabetes;
• disorders of the musculoskeletal system (especially osteoarthritis – an extremely disabling degenerative joint disease);
• some cancers (including cancer of the endometrium, breast, ovary, prostate, liver, gallbladder, kidney and colon).

The risk of these noncommunicable diseases increases as BMI increases.

Childhood obesity increases the likelihood of obesity, premature death and disability in adulthood. In addition to the increased risk in the future, obese children also experience shortness of breath, are at increased risk of fractures, are prone to hypertension, early signs of cardiovascular disease, insulin resistance, and may experience psychological problems.

## How can you lower the health risks of obesity?

On an individual level, everyone can:

• limit the calorie content of your diet by reducing the amount of consumed fats and sugars;
• increase your intake of fruits and vegetables, as well as pulses, whole grains and nuts;
• engage in regular physical activity (60 minutes a day for children and 150 minutes a week for adults).