Simple ‘string test’ is ‘significantly better’ than BMI at detecting if your child is obese...

CHECKING your child’s waist-to-height ratio is a better measure of if they’re obese than body mass index (BMI), a study shows.

The simple test — which can be checked with a piece of string — detected excess fat in kids and teens more accurately than BMI, researchers found.

1

Dr Andrew Agbaje, of the University of Eastern Finland, said: “This study provides new 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.”

One in 10 children aged four to five were obese in England last year, while a further 12 per cent were overweight.

The numbers were higher in children aged 10 to 11, with nearly a quarter obese and 14.3 per cent overweight in the same year.

Experts have raised concern about soaring levels, with hospital admissions for obesity in under-17s surging 40 per cent in a year in 2021 to 2022.

The NHS announced last year it is setting up 10 more clinics for obese children to cope with bulging demand.

Obesity is linked with a range of deadly conditions, including heart disease, stroke, diabetes and various forms of cancer.

BMI is worked out solely by your height and weight, and can only tell you how much weight you have, rather than breaking it down into muscle and fat.

People with a "healthy" BMI can still carry too much visceral fat.

Previous research has shown waist-to-height ratios are a good way of measuring obesity and heart risk.

BETTER MEASURE

The latest study, published in Pediatric Research, looked at how effective it is in children.

Researchers measured fat mass of 7,237 children when they were aged nine, 11, 15, 17 and 24 to see how well the measure predicted obesity.

They found the average waist circumference-to-height ratio in childhood, adolescence, and young adulthood is 0.45.

To work out waist circumference-to-height ratio yourself, get a tape measure and measure the waist at the narrowest point after exhaling in cm. Measure height, too.

Divide the waist size by height to get your result, baring in mind 0.45 was the average for kids. Or, you can use an online calculator.

The string test is a cheat way of measuring your weight, described below.

Dr Agbaye said: “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 kid's waist circumference-to-height ratio.”