Body Mass Index (BMI): What is it and what is it for?

The Body Mass Index (BMI) is a measurement used in the field of health and nutrition to assess the relationship between a person's weight and height. It is a widely used tool to determine if a person is at a healthy weight, underweight, or overweight or obese.

What is body mass index?

The Body Mass Index (BMI) is a measure that relates a person's weight and height to obtain an estimate of body composition. It is calculated by dividing a person's weight in kilograms by the square of their height in meters (BMI = weight / height^2).
BMI is used to classify people into different weight categories, such as underweight, healthy weight, overweight, or obese. Although BMI does not provide a complete assessment of health, it is a useful baseline indicator for identifying potential weight and health problems.

Importance of BMI for Health

The BMI is an important indicator to assess a person's weight status and its possible association with health. A BMI within the healthy range is considered a protective factor against chronic diseases , such as type 2 diabetes , cardiovascular disease, hypertension , and certain types of cancer.
On the other hand, a BMI above or below the healthy range may indicate the presence of health problems. A low BMI may be linked to malnutrition, nutritional deficiencies, and an increased risk of osteoporosis. A high BMI is associated with an increased risk of obesity and its complications, such as type 2 diabetes, heart disease, hypertension, and musculoskeletal disorders.

The BMI is not only useful at the individual level, but it is also a tool that allows health professionals to assess the prevalence of overweight and obesity at the population level, which contributes to the planning of strategies for the prevention and control of related diseases. with the weight.

How BMI is Calculated

The calculation of the BMI is relatively simple and can be done using the formula mentioned above: BMI = weight (kg) / height^2 (m^2). However, there are also online calculators and mobile applications that make the calculation easier.

To calculate the BMI properly, the following steps must be followed:

1. Weight: Measure body weight using a scale, preferably in kilograms. It is important to weigh yourself without clothes and preferably on an empty stomach to obtain more accurate results.
2. Height: Measure height in meters using a meter stick or tape measure. It is advisable to measure yourself barefoot and maintain an upright and straight posture.
3. Once the weight and height values are obtained, the BMI can be calculated by dividing the weight in kilograms by the square of the height in meters. The result obtained is interpreted using a scale established by the World Health Organization (WHO) or other health institutions.

BMI Limitations and Considerations

Although the BMI is a useful tool, it has some limitations and important considerations that must be taken into account:

Body Composition: The BMI does not take into account body composition, that is, the proportion of fat , muscle, and bone in the body. Therefore, it does not distinguish between weight coming from fat and weight coming from muscle mass. A person with a significant amount of muscle mass may have a higher BMI due to the weight of the muscle mass, even though they may not necessarily have excess body fat.

Fat Distribution: The BMI also does not take into account the distribution of fat in the body. The accumulation of abdominal fat, especially around the internal organs, is considered a major risk factor for metabolic diseases, such as insulin resistance and metabolic syndrome. Two people with the same BMI can have very different body fat distributions and therefore different health risks.

Individual Context : Each person is unique and has different physical, genetic and health characteristics. BMI cannot account for all of these individual factors, so it is important that BMI results be interpreted in the context of each person's medical history and overall assessment of health.

While it does not provide a complete assessment of health, BMI is a valuable baseline indicator for identifying potential weight and health problems. Calculated using a simple formula, BMI helps individuals and healthcare professionals get a general idea of a person's weight status and its possible association with chronic diseases. However, it is essential to consider the limitations of the BMI and evaluate the individual situation of each person to obtain a more accurate picture of their health .