Ann Arbor, Mich. --- Body mass index, a well-known method used to determine overweight and obesity in children, may not be the best way to describe distribution of body fat.

Rather the size of a child's neck may better predict childhood obesity, according to a study by the University of Michigan Health System published in the August issue of Pediatrics.

BMI does not adequately describe regional distribution of fat, such as in the upper body, which is a better indicator of some obesity-related complications such as hypertension, diabetes and heart disease.

 Olubukola O. Nafiu, M.D., Olubukola O. Nafiu, M.D.,    a pediatric anesthesiologist at the U-M Health System, and his colleagues, examined the usefulness of measuring neck circumference to identify children with high BMI by taking measurements of more than 1,100 children aged 6 to 18 years old.

They found neck circumference correctly identified a high proportion of young children and adolescents who were overweight or obese. For example, a 6-year-old boy with a neck circumference greater than 28.5 centimeters is nearly 4 times more likely to be overweight or obese than a boy with a smaller neck size.

Study authors suggest neck circumference is a simple technique that could be used to screen for overweight and obesity in children.

Additional U-M authors include Kevin K. Temper, M.D., chair of the Department of Anesthesiology, Constance Burke, BSN,  Joyce Lee, M.D., MPH , Terri Voepel-Lewis, MSN, and  Sobha Malviya, M.D., associate director of pediatric anesthesiology.