Cbi Or Body Roundness Index: An Indicator Favored By Doctors

Until now, to determine if a patient was overweight or obese, doctors used the BMI, the famous body mass index. Today, this calculation is supplemented by a new, more precise indicator. We invite you to discover the BRI or body roundness index in 5 questions.

1- What is the difference between BMI and CKD?

So far, the reference tool for measuring a person's corpulence has been the BMI or Body Mass Index. As a reminder, this indicator recognized by the World Health Organization is calculated by dividing an individual's weight by their height squared.

The result obtained allows determining if the person is overweight or obese:
• when the BMI is between 18.5 and 24.9, the patient's corpulence is considered normal.
• when this figure is between 25 and 29.9, the patient is at increased risk of being overweight.
• above 30, the patient is at increased risk of obesity.

Today, this calculation method is increasingly challenged by the scientific community. To address the shortcomings of the BMI, scientists propose using in addition the Body Roundness Index or BRI, calculated using a more complex formula. Unlike its predecessor, this new indicator takes into account the person's waist circumference. Indeed, visceral fat is a recognized marker of cardiovascular risk.

2- Why is the IRC considered more relevant by doctors?

In a study published on June 5, 2024, in the journal Jama Network Open, an international team of researchers estimates that the body roundness index is more reliable than BMI for assessing patients' physical condition.

The authors of this article explain that this new indicator is more relevant for diagnosing overweight or obesity and for measuring the risk of associated health problems, such as metabolic disorders, cardiovascular diseases, and cancers. This new, more complex calculation has the advantage of addressing the shortcomings of the body mass index.

3- What are the limitations of the body mass index?

The body mass index or BMI is a tool recognized by science. Its main advantage is to provide an initial objective assessment of a person's corpulence, as patients often have a subjective and erroneous view of their own bodies. Many women of normal build consider themselves too fat. Conversely, obese patients sometimes underestimate their overweight and the risks to their health.

Despite its usefulness, BMI is not a perfect and universally applicable indicator. It is based on standard profiles of healthy middle-aged adults. Its main flaw is that it does not take into account certain important parameters such as age, sex, and muscle mass of an individual. It does not distinguish between body fat and muscle mass.

This is why this overly general index is not relevant for children and adolescents, pregnant or breastfeeding women, seniors, and very muscular individuals. The "weight divided by height squared" calculation gives erroneous results for people with atypical builds and athletes like judoka Teddy Riner, for example. With his height of 2.04 meters and his weight around 130 kg in competition, the French champion would be considered obese with a BMI over 31.

4- Should we stop calculating BMI?

The body mass index is a simple and practical international tool for conducting epidemiological studies or for making the initial diagnosis of potential overweight. Even though it has been criticized, it is not a question of completely forgetting this indicator, but rather complementing it with other more precise calculations. This is where the new body roundness index comes in, based on a greater number of anthropometric variables.

This index was developed in 2013. It takes into account height, weight, but also waist circumference and sometimes the hip circumference of the person. In fact, nutritionist doctors have now become accustomed to systematically measuring the abdominal waist circumference of their patients.

The only problem with the BRI is that its calculation is more complicated than that of the BMI. To obtain a reliable result, a calculator used by nutrition professionals is needed.

5- What is the purpose of the body roundness index?

In addition to BMI, the calculation of the body roundness index serves to predict not only overweight but also metabolic diseases. Unlike BMI, BRI allows for measuring visceral fat, which is a cardiovascular risk factor.

This type of fat that surrounds the viscera and organs is particularly harmful to health. It hinders the proper functioning of certain organs such as the liver, and this can of course have repercussions on the person's metabolism.

Did you know that excess fat in the thighs or legs is less dangerous to health than excess fat in the abdomen? The body mass index does not differentiate between these two distributions of fat in the body, but BRI does! This nuance explains why men who store fat in the abdominal area are more exposed to cardiovascular diseases and type 2 diabetes than women who have saddlebag fat...

Because it is more comprehensive than BMI, the body roundness index is more effective in estimating patients' mortality risk. The authors of the previously cited study nevertheless recommend using both calculation methods together to optimally assess the health status of patients.