More young US children become overweight or obese during summer vacations than during the school year.

Researchers examined body mass index (BMI) and obesity prevalence in a nationally representative sample of 18,170 children from the start of kindergarten in 2010 through the end of second grade in 2013.

Summer Vacations
Image source: Wikimedia Commons
Summer Vacations

The findings, published in the journal Obesity, show that between the start of kindergarten and the end of second grade, the prevalence of obesity increased from 8.9 percent to 11.5 percent, and the prevalence of overweight children increased from 23.3 percent to 28.7 percent. All of the increases occurred during the two summer vacations, not during the three school years.

The study is the second nationally representative analysis of seasonal BMI gain. The first, which was coauthored by von Hippel and published in 2007 in the American Journal of Public Health, found that children gained weight faster during summer vacation than during the kindergarten and first-grade school years.

More soda, fewer veggies for kids in the summer

However, that earlier study only followed children through first grade. Further, the results are outdated since the children who participated are now in their early 20s.

“I wish I could say that changes schools have made over the last decade are helping to reduce obesity, but they’re not,” von Hippel says. “Schools have never been a big part of the obesity problem.

“What we’re seeing in elementary schools today is the same thing that we saw in 1998-2000; kids are gaining BMI at healthy rates during the school year, and then becoming overweight when school lets out. We can’t make a dent in this problem if we continue to focus on school food and physical education programs that affect children only when they’re at school.”

School-based programs should try to change children’s behaviors not only when they are in school, but also when school is out, von Hippel says.

In addition, work is needed outside schools to limit child-directed food marketing, promote out-of-school activities such as summer schools and summer camps, reduce screen time, and educate parents about nutrition.

The Russell Sage Foundation supported the work.

Source: University of Texas at Austin

Original Study DOI: 10.1002/oby.21613