A new indicator for our weight: the Body Roundness Index

Should we forget the BMI, the body mass index, to now take into account the CRI, the body roundness index? This is what several researchers propose in any case.

Chinese and American researchers are proposing a new indicator to monitor the overweight of the population, and better assess the effects of obesity on health, CRI, body curvature index. Explanations from Mathilde Fontez, editor-in-chief of the magazine Epsiloon.

franceinfo: Perhaps we should already remember what the current index, the BMI, is?

Mathilde Fontez: Yes, for the moment, the indicator recognized by the World Health Organization is BMI, body mass index. The formula is simple: your weight (in kilos), divided by your height (in meters) squared, this gives a number around 20 for healthy people. Above 25 is overweight, above 30 is obesity.

The new index proposed by this team is based on waist circumference. This is a formula that evaluates body shape, rather than just height to weight ratio. Researchers call it the body curvature index, BRI.

We no longer take weight into account?

No ! This comes from research that is beginning to show that being overweight is not necessarily associated with health risks: it often is, but not always. So you have to be more subtle than that. An obesity specialist, Ruth Loos, at the University of Copenhagen, for example, showed that 15 to 45% of obese people based on their BMI would actually be in good metabolic health. The fears are of missing certain diseases or of poorly assessing the risks for the population in the major statistics.

What is at stake?

The latest WHO report estimates that in Europe, almost two thirds of adults and one in three children suffer from overweight or obesity. Of course, the best assessment remains the complete individual study of each patient: blood tests, family history, even genetic tests. But with this new indicator, the researchers propose to refine while remaining simple: they started from the observation that visceral fat, that which is buried deep in the body, is a good marker of the risk of diseases, a visceral fat located in particular to the size… Hence this index of body roundness.

How is this new IRC perceived?

This is the whole purpose of this study (in English) which has just been published. Researchers reviewed the medical records of more than 30,000 people in the United States over 20 years, between 1999 and 2018, to evaluate the association between their body roundness index and mortality risk. In fact, they found certain characteristics of the BMI but they also saw a correlation with mortality for very high CRI. In short, a first validation for this body roundness index.