Feb. 28, 2007 -- Childhood obesity may peak during summer break, not during the school year.
A new study shows that kindergarteners and first-grade students are more likely to gain extra weight during summer break than during the school year.
If so, the most productive ways to help children reach and maintain a normal weight "will be those that target children's behavior not only during school hours but also, and most important, after the school bell rings," write the researchers.
They included research statistician Paul von Hippel, PhD, of Ohio State University's sociology department and sociology professor Brian Powell, PhD, of Indiana University at Bloomington.
Problem ‘Outside Schools’
"We really can't blame schools for the rise in childhood obesity. The problem is primarily outside of schools," says von Hippel in an Ohio State University news release.
School schedules and physical education classes may curb kids' weight during the school year, but that all goes out the window during summer break, he notes.
"This isn't to say that schools can't improve," Powell says in an Indiana University news release.
"When I read about school budgets being cut, resulting in cuts in physical education or after-school programs, I now think, 'What will happen in terms of children's weight?'" Powell says.
Brown, von Hippel, and colleagues studied data on 5,380 children at 310 elementary schools nationwide.
Researchers visited the schools to measure the kids' height and weight four times: at the beginning of kindergarten, at the end of kindergarten, at the beginning of first grade, and at the end of first grade.
The researchers used those measurements to calculate the children's BMI (body mass index). They found that BMI grew fastest during summertime.
"During summer vacation, average BMI growth was more than twice as fast as during either school year," the researchers write.
It's natural for kids to gain weight as they grow. But von Hippel's team sees no clear reason why growth should be particularly fast during the summer.
"This study raises questions that the data cannot fully answer," the researchers write. For instance, they don’t know if the kids ate more or exercised less during summer break, or whether the results apply to older students.