Measuring body mass index (BMI) is not a reliable measure of its diagnosis obesity and can lead to an incorrect assessment, according to the Committee on Clinical Obesity of the journal “The Lancet”.

The Commission recommends a new differentiated approach, where measurements of body fat, as well as symptoms of ill health at the individual level, will be used in addition to BMI to detect obesity.

Today obesity is defined by BMI: it is assumed that BMI over 30 kg/m2 is an indicator of obesity for people of European descent. However, scientists point out that the current diagnostic approach is prone to misclassification of excess body fat and misdiagnosis of the disease.

Although BMI is a useful indicator, the Commission stresses that it is not a direct way of measuring fat, does not reflect its distribution throughout the body and does not provide information about health and disease at an individual level.

“Some people tend to store excess fat around the waist or in and around their organs, such as the liver, heart or muscles, and this is associated with a higher health risk than when excess fat is stored just below the waist. skin on the hands, feet or other areas of the body,” explains University of Colorado Anschutz Medical Campus professor and Commission member Robert Eckel.

The Committee recommends at least one measurement of body size (waist circumference, waist-to-hip ratio, waist-to-height ratio) along with BMI, at least two measurements of body size independently of BMI, and a direct measurement of body fat independently by BMI.

In addition, the scientific team introduces two new diagnostic categories of obesity based on objective measures of the disease at the individual level. These are ‘clinical obesity’, i.e. chronic disease associated with ongoing organ dysfunction and due to obesity alone, but also ‘preclinical obesity’ associated with a variable level of health risk but no current disease.

It is estimated that more than one billion people in the world live with obesity, and the Commission’s recommendations call for a universal definition of obesity and a more accurate method for its diagnosis.

The Commission’s findings were published in The Lancet Diabetes & Endocrinology journal.