Measuring waist circumference to height ratio has be found to be more accurate than using body mass index (BMI) for identifying obesity in children.
In a detailed 15-year study of 7,237 children which compared both measurements with DEXA-scans, waist circumference to height ratio was found to be more accurate at distinguishing between fat and muscle.
Publishing the findings in Pediatric Research, the UK and Finnish team said the findings add to the call to move away from use of BMI in children which lead to them being mislabelled as overweight or obese.
It follows other research in adults suggesting that waist circumference-to-height ratio predicts premature death better than BMI.
The study used data from the Avon Longitudinal Study of Parents and Children whose BMI and waist circumference-to-height ratio were measured at ages 9, 11, 15, 17, and 24 years.
Researchers showed that waist circumference to height ratio was more likely to ‘agree’ with fat mass measured on a DEXA scan than muscle mass whereas BMI was linked to both.
Ultimately the use of weight circumference to height ratio could identify eight out of ten males and seven out of ten females who truly had excess DEXA-measured fat.
But it could also identify 93 out of 100 males and 95 out of 100 females who truly do not have excess fat.
Study author Dr Andrew Agbaje, a physician and paediatric clinical epidemiologist at the University of Eastern Finland, said: ‘This study provides novel information that would be useful in updating future childhood obesity guidelines and policy statements.
‘Waist circumference-to-height ratio might be preferable to BMI assessment in children and adolescent clinics as an inexpensive tool for detecting excess fat.
‘Parents should not be discouraged by the BMI or weight of their children but can inexpensively confirm whether the weight is due to increase in excess fat by examining their child’s waist circumference-to-height ratio.’
Figures from the National Child Measurement Programme published in January show that an increase in levels of overweight and obesity seen in the pandemic has not reversed in older primary school children.
There has been a 45% increase in rates of overweight and obesity during the pandemic – the largest single year rise recorded – believed to be a result of school closures and cancellation of sports clubs at the start of the pandemic, as well as disruption to normal activity routines.
Last summer the NHS announced plans to open 10 new specialist clinics across England to support children and young people who are severely obese.
The rise in rates of obesity and overweight seen in the pandemic was twice as high in the most deprived areas of England – a gap that is widening over time.
