World news and discussion on TalkFuse.
BMI alternative for identifying obesity ‘could prevent misdiagnosis in millions’
Experts say combining BMI with body measurements and tests of organ function could improve obesity diagnosis and care. Their analysis suggests BMI alone misses obesity in 5% to 9% of adults and wrongly labels up to 3%, potentially affecting tens of millions of people.
Researchers analysed health records from more than 800,000 people in the UK, US, China and Spain, tracking health for up to 15 years. The proposed method uses BMI alongside waist measurements and waist-to-height ratio, then distinguishes clinical obesity, where excess fat impairs organ function, from pre-clinical obesity, where it poses a risk without current impairment. Under this definition, only about a quarter to a third of people classified as obese had clinical obesity; 80% to 90% of those with pre-clinical obesity did not progress to clinical obesity within 10 years.
In short
- BMI alone can miss or misdiagnose obesity.
- A proposed approach adds body measurements and organ function tests.
- Most people with pre-clinical obesity did not develop active disease within 10 years.
Steelman: both sides, in good faith
The strongest fair case each way — we don't pick a winner.
The case for
BMI alone can miss people whose excess fat is harming their health and can misclassify others, so adding waist measurements and evidence of organ function may support more accurate diagnoses and care. Distinguishing current impairment from future risk could also avoid treating everyone above a threshold as equally ill, while still allowing monitoring and prevention.
The case against
A more complex definition may be harder to apply consistently and could make diagnosis depend on measurements or tests that are not equally accessible. Separating clinical from pre-clinical obesity might also lead some people at elevated risk to receive less attention, even though their condition could worsen and the proposed categories may not capture every individual’s circumstances.
Explained simply
Body mass index (BMI) estimates body fat using a person’s weight and height. It is widely used to identify obesity, but it does not show where fat is carried or whether it is affecting someone’s health.
Doctors and researchers have debated how obesity should be defined and assessed. The proposed approach combines BMI with waist measurements and checks whether excess fat is impairing the function of organs such as the heart or lungs.
The distinction matters because people can have excess body fat without current organ problems, while others may face health effects that BMI alone does not reveal. A more detailed assessment could help guide care, while recognising that some people at risk may not develop related illness.