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Weight Gain In When School's Out

— Out-of-school factors appear to drive kids' overweight and obesity

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NEW ORLEANS -- Young children are at a higher risk for obesity during summer vacations, according to the findings of the Early Childhood Longitudinal Study, presented at Obesity Week 2016.

In a large group of kindergarten children followed until they finished 2nd grade, prevalence of obesity and overweight increased from 8.0% to 11.5% and 23.3% to 28.7%, respectively -- and all of the children's weight gain occurred during the summer, reported , of the University of Texas at Austin.

Action Points

  • Note that this study was published as an abstract and presented at a conference. These data and conclusions should be considered to be preliminary until published in a peer-reviewed journal.

Overall prevalence rates for obesity and overweight significantly increased by an average of 1 percentage point each month during the summer months (P<0.001). Conversely, during the school year, obesity prevalence slightly decreased by 0.1 points per month, while overweight prevalence did not change significantly. The study results were also published in the journal .

Von Hippel explained in his oral presentation the importance of looking outside of school to tackle rising overweight and obesity rates in youth.

Two suggestions he posed to the audience were parental education for nutrition and reduction of screen time for kids. Additionally, he also discussed how past observational research provided support for enrolling kids in structured summer environments such as camps to prevent obesity risk in children.

Ultimately, he said, randomized, controlled research is required on the benefits and protective effects of summer camps for kids.

A total of 13,006 kindergarteners from 846 schools were included in the 3-year study, which began in 2010. Measurements for height and weight were collected each fall and spring, for a total of six times.

With mean rates of growth measured during these time periods, BMI changes were faster during the summer, at 0.07 points per month, versus during the school year, at an average of 0.004 per month (P<0.0001). Additionally, standard deviations of BMI growth indicated rates were much more inconsistent in the summer months.

, of the Pennington Biomedical Research Center in Baton Rouge, La., who was not involved with the study, applauded the study for its unique approach. "A few studies have shown summer weight gain using local convenience samples," she told 鶹ý.

"This is the first study to use a nationally representative sample with longitudinal data that were objectively collected. In other words, we can be confident in the findings that there is a national trend for children in kindergarten to second grade to gain weight at a more rapid pace during the summer and not during the school year. It is surprising that these findings were consistent across age, sex, and socioeconomic status -- and that summer weight gain persisted regardless of more traditional protective factors.

"This study indicates that summer is the key time for overweight and obesity to increase in children, whereas the school year seems to stabilize the obesity prevalence," added Staiano, who is a spokesperson for The Obesity Society. "Based on other studies, it is likely the standard breakfast/lunch, set sleep schedule, and standard physical activity during the school year is stabilizing weight gain. On the other hand, it is likely the unstable sleep schedule, high TV viewing with exposure to food ads, and low levels of physical activity in hot climates are driving the summer weight gain.

"As researchers, public health officials, and parents, we need to structure children's summers so that they eat healthy, sleep on a regular schedule, and get at least 1 hour of physical activity every day," Staiano urged.

Von Hippel and colleagues noted that the "out-of-school risk factors" identified in the study may not be limited solely to summer vacations. A similar effect could possibly occur on weekends, but that was not examined in the current study.

  • author['full_name']

    Kristen Monaco is a senior staff writer, focusing on endocrinology, psychiatry, and nephrology news. Based out of the New York City office, she’s worked at the company since 2015.

Disclosures

The study was supported by a grant from the Russell Sage Foundation.

The authors disclosed no conflicts of interest.

Primary Source

Obesity

Von Hippel T, et al "From kindergarten through second grade, U.S. children's obesity prevalence grows only during summer vacations" Obesity 2016; DOI: 10.1002/oby.21613.