Medical experts have called for new way to more accurately measure obesity, although definition has yet to be adopted

Almost 70% of adults in the US would be deemed to have obesity based on a new definition, research suggests.

The traditional definition of obesity, typically based on having a body mass index (BMI) of 30 or greater, has long been controversial, not least as it does not differentiate between fat and muscle.

In an effort to tackle the issue, in January medical experts from around the world called for a new definition. This would encompass people either with a BMI greater than 40; or those with a high BMI and at least one raised figure for measures such as waist circumference, waist-to-hip ratio, or waist-to-height ratio; or those with two such raised figures regardless of BMI; or those with direct measures of excess body fat based on scans.

In addition, they said obesity should be split into two categories: clinical obesity – where there are signs of illness – and pre-clinical obesity, where there are not.