New Research Suggests BMI Alone May Not Accurately Identify Everyone With Obesity-Related Ill Health

Body mass index, or BMI, is widely used to classify people according to their weight in relation to height. Although it is useful for population-level screening, it does not directly measure body fat distribution or determine whether excess body fat is causing health problems.

Researchers examined a proposed framework that separates obesity into preclinical and clinical categories. Preclinical obesity refers to excess body fat that may increase future health risks without clear evidence of current organ dysfunction. Clinical obesity refers to excess body fat associated with demonstrable health problems.

The study analysed data from nearly 850,000 adults across four countries. Under the proposed framework, researchers estimated that only around 27% of people classified as obese using conventional BMI-based criteria had clinical obesity.

The proposed approach also considers measurements such as waist circumference and evidence of related conditions affecting organs, including the heart and liver.

The findings could influence how healthcare professionals assess obesity risk and decide when medical intervention is needed. However, the framework does not mean that people without current organ dysfunction have no health risks.

Physical activity, strength training, balanced nutrition and individualised weight-management support remain important components of long-term health.