PHILADELPHIA -- In the first study of how weight may affect school attendance, researchers at the University of Pennsylvania and Temple University have found that overweight children are at greater risk of school absenteeism than their normal-weight peers.  The study of more than a thousand 4th, 5th and 6th graders in the Philadelphia school system also determined that body mass index, or BMI, is as significant a factor in determining absenteeism from school as age, race, socioeconomic status and gender, formerly the four main predictors.

The study found that overweight children were absent on average 20 percent more than their normal-weight peers.

"At this young age, children are not necessarily experiencing the health problems that will likely confront them later in life unless serious intervention takes place," said Andrew B. Geier, a doctoral candidate in the Department of Psychology in the School of Arts and Sciences at Penn.  "However, they are missing school at a greater rate than their peers, setting themselves up for the negative fallout that accompanies absenteeism.  What's keeping them from school, more than heath issues, is the stigma and the bullying that accompanies being overweight.  Future research should explore this additional, very damaging side effect of being overweight."

The study builds on others that show that the medical and psychosocial consequences of being overweight are numerous and still being discovered.  The disadvantages that arise from missing school such as increased drug use, increased rates of pregnancy and poor academic performance have been previously documented.  Meanwhile, the rate of childhood obesity has tripled in the United States during the past 25 years.

The four indicators of increased absenteeism among school children have traditionally been race, socioeconomic status, age and gender.  Young men from economically disadvantaged, minority populations were considered at greater risk for school absenteeism, and that remains true; however, in this study, BMI was a better indicator of poor classroom attendance than these traditional factors or any others.

Researchers attempted to control for the socioeconomic differences among students by selecting inner-city schools that were homogeneously among the city's poorest.  More than 80 percent of students at these schools were eligible for free and reduced-cost meal plans.

The findings are reported in the August issue of the journal Obesity.

In addition to Geier, the researchers are Jackie McLaughlin, Shiriki Kumanyika and Justine Shults of the Department of Psychology in Penn's School of Arts and Science; Gary Foster, Leslie Womble and Kelley Borradaile of Temple University; Joan Nachmani of the School District of Philadelphia; and Sandy Sherman of The Food Trust.

The research was supported by the National Institutes of Health.