June 12, 2014 at 12:02 PM ET
School districts nationwide have been banning sugary drinks and fat-laden lunches to help curb rampant obesity among students, but a new analysis suggests that summer is actually when kids pack on more pounds.
Researchers at the Harvard School of Public Health looked at data from seven studies that included more than 10,000 kids ages 5 to 12 in the United States, Canada and Japan. In all but one of the studies published between 2005 and 2013, the findings suggested that weight gain accelerated among kids during the summer — mostly for black and Hispanic youngsters and children and teens who were already overweight.
“It’s especially those kids who are already at risk who are the most at risk during the summer,” said Rebecca Franckle, a Harvard doctoral student who led the study published in the journal Preventing Chronic Disease.
In one study of more than 5,300 kindergarten and first-graders in 310 U.S. schools, researchers found that the kids’ body mass index growth, one measure of excess weight, was more than twice as fast during summer vacation as during the school year.
“Although schools may not provide ideal environments for healthy BMI growth, it appears that they are healthier than most children’s non-school environment,” researchers concluded in the 2007 study in the American Journal of Public Health.
About a third of children and teens in the U.S. are either overweight or obese, according to federal health estimates. Piling on extra weight at a young age can lead to serious health problems later in life.
Researchers can’t be certain what’s behind the summer weight surge in kids, but Franckle said they suspect that it’s less structure, extra snacks, boredom and more time engaged in sedentary activities like video games.
More research is needed to determine the best ways to curb weight gain over the summer, but Franckle suggested that parents worried about extra pounds should look to the school year for suggestions. Engaging kids in structured sports or camp programs and expanding access to summer food programs for low-income children might help, for instance.
“What can we do to mirror those healthy environments, to mirror those healthy trends?” she said.