One in five adults living with overweight could be reclassified as obese under new framework

A new study has found that one in five adults living with overweight in the United States could be newly classified as living with obesity under a revised definition developed by the European Association for the Study of Obesity (EASO).

The research, published in Annals of Internal Medicine, analysed health data from more than 44,000 adults and suggests that the new framework may offer a more sensitive approach to diagnosing obesity-related disease earlier than using body mass index (BMI) alone.

The EASO framework incorporates additional anthropometric measures and clinical comorbidities to define obesity, rather than relying solely on BMI. However, until now, it had not been validated in large population studies.

Researchers from Ariel University, Tel Aviv University, and the Holon Institute of Technology applied the EASO definition to data from the National Health and Nutrition Examination Survey (NHANES), covering US adults aged 18 to 79 between 1999 and 2018. They found that 18.8 per cent of people previously categorised as living with overweight by BMI would now be reclassified as living with obesity.

Among those newly identified as living with obesity, common health complications included hypertension (79.9 per cent), arthritis (33.2 per cent), diabetes (15.6 per cent) and cardiovascular disease (10.5 per cent).

Importantly, the mortality risk for this group was similar to that of adults with a normal weight. In contrast, those with a BMI of 30 kg/m² or above had an almost 20 per cent higher risk of death.

When compared with adults of normal weight who had no major health issues, those newly classified as living with obesity under the EASO framework had a 50 per cent higher risk of death. However, this risk was not greater than that seen among individuals of normal weight who had comorbidities.

The findings indicate that the EASO framework may better reflect obesity-related health risk and could lead to earlier interventions. The researchers recommend further studies to assess whether individuals newly diagnosed using this framework would benefit from targeted obesity treatment.