Obese elementary schoolchildren miss a couple more school days on average than their normal-weight classmates, according to a study that says being fat is a better predictor for absenteeism than any other factor.
Researchers said their results suggest that childhood obesity, in addition to serious medical issues, can lead to a host of additional problems down the road.
"It's clear in all the literature that the more days of school you miss, it really sets you up for such negative outcomes: drugs and AIDS and (teen) pregnancy," said Andrew B. Geier, a doctoral candidate at the University of Pennsylvania and lead author of the study released Friday.
He said the findings should serve as a clarion call to school officials.
"At this early age to show that already they're missing school, and missing school is such a major setup for big-time problems, that's something school policy people have to know," Geier said.
The researchers from Penn and Temple University looked at 1,069 fourth- to sixth-graders for one academic year in nine Philadelphia schools, where teachers took attendance each morning. Based on body mass index, a standard measure of height and weight, each child was classified as underweight, normal weight, overweight or obese.
Of 180 school days, researchers found that on average the normal weight students missed 10.1 days, overweight kids missed 10.9 days and obese children missed 12.2 days. For reasons that aren't clear, underweight children had the fewest absences — 7.5 on average.
In decades of research about student performance, race, socioeconomic status, age and gender have been tagged as the top predictors for absenteeism. The new study, in the latest issue of the journal Obesity, concludes that weight tops them all, Geier said.
The study didn't explore why the children missed school. Researchers theorize it's got less to do with medical issues — many children at this young age haven't yet developed major obesity-linked maladies — and more to do with the stigma of being fat.
"They're missing school because they don't want to be bullied and called names," Geier said.
Researchers tried to make the test group as homogeneous as possible by picking schools that were among the city's poorest, with the assumption that education and income levels would be fairly even.
Nationally, obesity rates have nearly quintupled among 6- to 11-year-olds and tripled among teens and children ages 2 to 5 since the 1970s, according to the Centers for Disease Control and Prevention. Obesity can lead to diabetes, high blood pressure and cholesterol, sleep apnea and orthopedic problems.
The study adds to growing research into non-medical complications of being fat, including data suggesting that obese adults miss more workdays and go to college less frequently than people of normal weight, Geier said.
"This is exactly the kind of study that will get the attention of policy makers," said Jim Bogden, healthy eating project coordinator for the National Association of State Boards of Education. "The correlation with absenteeism is very powerful."
He likened the results to studies linking academic achievement to participation in school breakfast programs — research that prompted lots of schools to start offering such programs. In this case, changes could include anything from improving nutrition education and cafeteria offerings to getting parents to serve healthy meals at home.
"Those of us working in school health do all we can to publicize this information, and it seems to be starting to sink in," Bogden said