An international team of researchers from China, the United States, Spain, Italy and the United Kingdom analyzed medical data from 844,108 adults in those countries and concluded that relying on body mass index (BMI) alone underestimates the true prevalence of obesity and cannot accurately predict the risk of premature death. The findings were published in the journal Nature, infohub.kz reports.
Instead of calculating BMI in isolation, the researchers tested criteria set by a Lancet commission that take into account waist circumference, the waist-to-height ratio and the presence of organ dysfunction, the medical portal News-Medical writes.
The authors examined four large databases: China's Kailuan study, the UK Biobank project, the U.S. All of Us program and Spain's SIDIAP system. They found that classic BMI wrongly diagnosed obesity in 1.2–3.1% of participants while missing it in 5.2–8.6% of people with a dangerous fat distribution. Adding waist measurements raised the detected share of people with obesity by 3.3–7.4 percentage points, depending on the country.
The researchers also divided patients' conditions into clinical obesity — when excess fat already impairs organ function or daily activity — and preclinical obesity, in which bodily functions remain intact. People with clinical obesity had a 69% higher risk of death from all causes, whereas in the preclinical form the risk rose by only 19%, and most such patients did not progress to a severe stage over 10 years of follow-up.
According to the scientists, the new approach will help doctors choose more precisely between intensive and preventive treatment.