Even experts who love the Body Mass Index calculation agree that it has its limitations. It can figure out whether at kid is heavier than average for her size, but it doesn’t distinguish where the heaviness is coming from. It sort of assumes a standard amount of muscle and assumes anything beyond that is fat. Staking everything on BMI results.

Also ignores what researchers find important  where fat is showing up.But a new test, specifically for children, can more accurately determined whether a child is carrying around an excess amount of fat, instead of simply being strong and sturdy. It also shows whether the fat is showing up in the wrong places. And it’s pretty simple: measure the child’s neck.

The online journal, Pediatrics, reports the results of a study from the University of Michigan’s Mott Children’s Hospital. Doctors measured the neck circumference of more than 1,000 children and grouped them into two ages, 6 to 10 and 11 to 16, and also divided them by gender.

Researchers found that the neck circumference more accurately correlated with the child’s height, weight, waist circumference, BMI and age than BMI alone. whether a child was, in fact, overweight or obese — or just simply heavy (due to muscle, etc.) Large necks, the researchers say, have a strong correlation with a lot of fat around the torso, which, in turn, has been strongly linked to heart disease and diabetes.

The test works on kids rather than adults, who often develop strong and muscular necks — which would throw off the reading in the same way muscles throw off BMI. BMI has long been an oppressive number to many people trying to get a handle on their health and their children’s health. The neck test sounds promising.