The new screening - for all kindergartners through fourth graders - is part of an effort to identify kids early who are candidates for a lifelong weight problem - and the ailments that can accompany it - from diabetes to heart disease.
"This is a way of protecting children's health," says Beth Trapani, a spokeswoman for Pennsylvania Advocates for Nutrition and Activity, a statewide coalition of public, private, academic, professional and volunteer groups. "It is an attempt to raise awareness."
While the prevalence of overweight children has soared in a generation - more than doubling in 25 years - many parents are unaware or don't want to admit that their child has packed on too many pounds, Trapani says. Larger kids simply do not stand out as they once did, she says.
"Our ability to recognize whether a child is at a healthy weight has deteriorated as our nation's waistline has expanded," says Trapani, whose group helped the Pennsylvania Department of Health to implement the state's new BMI policy.
Pennsylvania started BMI screenings in a few schools two years ago and learned that nearly 40 percent weighed too much, according to Jon Dale, Pennsylvania health department's director of school health.
By routinely measuring BMI, Pennsylvania steps onto potentially controversial terrain. The Institute of Medicine last year suggested BMI screening in schools to catch weight problems when it is more possible to "prevent further increases and perhaps lower BMI."
But the value of the screening is still unproven. There isn't enough evidence indicating whether it can help prevent obesity and its health-related problems, according to a U.S. Preventive Services Task Force report published in the journal Pediatrics this summer. The task force did not take a position on whether the screenings should be done routinely.
"The BMI is a screen; it is not a definitive diagnosis," says Dr. Sandra Hassink, director of the weight management program at Alfred I. duPont Hospital for Children in Wilmington. "It gets you in the doctor's door."
Once there, she says, the doctor should put the results in context: For a lean high school athlete who has been lifting weights all summer, a high BMI likely would not signal a problem. His heft comes from muscle, not carrying too much fat. But for an inactive teen, it could be a prelude to a future health problem.
"If nothing else, it gets a conversation going between the pediatrician and the family," says Gary Foster, clinical director of the Weight and Eating Disorders Program at the University of Pennsylvania School of Medicine. "It may not cure the obesity epidemic. . . . It will increase awareness of the problem."
A few states, including Florida and California, have used BMI screenings in schools. And Illinois is starting to require students entering kindergarten, fifth and ninth grades to provide BMI data as part of their health records, according to Mary McKenna, a health scientist at the Centers for Disease Control and Prevention. (New Jersey does not require BMI screening, according to state education officials.)
Arkansas has probably the best known and biggest program, screening 450,000 students a year. It started two years ago as part of a broad effort to tackle childhood obesity. In the first year, the state discovered that 38 percent of its schoolchildren weighed too much for their height, age and gender. Once sliced, the data revealed that no area of the state or group was immune from the epidemic.
Joy Rockenback, program director for Arkansas' Body Mass Index Initiative, says the BMI screenings helped people focus on leading healthier lives. Some schools, for instance, limited snack foods at parties and community groups assessed the condition of parks and sidewalks.
But the BMI initiative also got nearly 100 phone calls, with people complaining that the program overstepped its bounds by reporting the data, she says. They felt government had enough to do without telling them how to raise their kids. And the schools should provide healthier meals and more exercise before telling parents there was something wrong with their children.
The state anticipates releasing its second-year results in a few weeks, Rockenback says.
Pennsylvania plans to roll out its BMI screening in public schools over the next few years, starting with kindergartners through fourth graders this year, according to state officials.
The confidential information is supposed to be sent home, and parents will learn in what category their child's BMI is: overweight, at risk for overweight, underweight or normal. If children fall outside the normal range, the state advises that parents consult their physician.
"The parents have a right to know the information from screens" and choose what to do with it, says Dale.
Marge Ewing, a nurse in the Marple Newtown School District, started BMI screenings last year to prepare for the state program. She went to the parent-teacher organizations beforehand to give them a heads up. And, when the results went home to parents, she says, she didn't get any complaints.
"I don't think there are any disadvantages to it, when it's taken in the spirit the state intends," says Ewing.
Contact staff writer Marian Uhlman at 215-854-2473 or firstname.lastname@example.org.
What You Can Do
Provide healthy food and drinks at home.
Teach children how to make good food choices based on nutrition, calories and portion sizes.
Encourage physical activity.
Limit TV viewing and computer time.
Talk to the family doctor about a child's BMI.
Be a positive role model.
Source: Preventing Childhood Obesity, Institute of Medicine 2004