Free day camp could combat BMI gain among children during summer break

Key takeaways:

• Children tend to gain weight over the summer because of a lack of structured activities.
• Those who attended summer day camp saw reductions in BMI z scores, unlike children who spent their summer as usual.

Sending young children from low-income households to free summer day camps could help reduce gains in BMI during summer break, according to a randomized clinical trial in JAMA Pediatrics.

Children experience an estimated 2% to 3% increase in overweight and obesity each summer, and a 1% decrease over the school year, according to Michael W. Beets, PhD, MPH, MEd, professor of exercise science at University of South Carolina Arnold School of Public Health, and colleagues. The researchers said children from historically marginalized groups have an even higher risk for unhealthy weight gain over the summer.

“A leading explanation of this phenomenon is the structured days hypothesis,” Beets and colleagues wrote. “During the school year, children are consistently exposed to a structured setting that promotes healthy behaviors via environmental control.

“During the summer, school is no longer in session, removing access to an environment that may play a protective role for youth against unhealthy weight gain,” the researchers wrote.

Summer day camps can provide structure to children when school is not in session, but they can be cost-prohibitive for low-income families, Beets and colleagues wrote. In their study, they randomly assigned 223 children (54.7% boys; mean age, 8.1 years; standard deviation [SD], 1.5) to attend free programming every weekday for 6 to 8 weeks during the summer in 2021, 2022 and 2023. Another 199 children (49.3% boys; mean age, 8.2 years; SD, 1.5) served as the control group and spent their summer as usual. Most participants (69%) lived in households at or below 200% of the federal poverty level.

At the end of summer, the day camp group experienced a mean decrease in BMI z scores (zBMI) of –0.048 (standard error [SE], 0.025). In contrast, the control group had a mean zBMI increase of 0.046 (SE, 0.027), a difference of –0.094 (95% CI, –0.166 to –0.022).

Children’s zBMI decreased –0.034 to –0.018 for every extra day of the week that they attended summer camp, and those who attended every weekday experienced zBMI decreases between –0.09 and –0.04. Participants who never attended summer programming experienced zBMI gains between 0.046 and 0.08.

“Providing access to existing community-operated summer programming can serve as a viable intervention to address accelerated zBMI gain for children from low-income households,” Beets and colleagues wrote. “Because most municipalities have some form of summer programming, this intervention approach is readily available for many youth and potentially easy to implement if funds are available to support the cost.”