WEDNESDAY, April 8, 2020 (HealthDay News) -- One side effect of the coronavirus pandemic could be long-lasting: U.S. school closures may worsen the child obesity crisis, experts warn.

Previous research has shown that kids tend to gain weight when they're out of school during the summer -- especially Hispanic and black youngsters and children who are already overweight.

"There could be long-term consequences for weight gained while children are out of school during the COVID-19 pandemic," said Andrew Rundle, who studies ways to prevent childhood obesity. He's an associate professor of epidemiology at Columbia University Mailman School of Public Health in New York City.

"Research shows that weight gained over the summer months is maintained during the school year and accrues summer to summer," Rundle said in a university news release. "When a child experiences obesity, even at a young age, they are at risk for higher, unhealthy weight, all the way into middle age."

Rundle and his colleagues predicted that COVID-19-related school closures will double out-of-school time this year for many children in the United States. And that, in turn, will aggravate risk factors for unwanted weight gain, they warned.

Social distancing and stay-at-home orders limit opportunities to exercise, particularly for city kids living in small apartments. As a result, inactivity, screen time and snacking are likely to increase, Rundle and colleagues wrote in their study published recently in the journal Obesity.

They also noted that families stocking up on long-lasting food sources tend to focus on ultra-processed, calorie-dense comfort foods.

The authors outlined ways to prevent children from gaining weight during the coronavirus pandemic:

• To reduce food insecurity, which is associated with unhealthy weight among kids, some school districts are offering students grab-and-go meals at school sites or on buses that run along their regular pick-up routes.
• Farmers markets often provide specialty and ethnic produce and prepared foods sought by immigrant communities. Cities and states should consider them part of essential food services, but also create social distancing plans for such markets, Rundle and colleagues recommended.
• As schools switch to remote teaching, they should make physical education a priority, with home lesson plans for physical activity and/or streaming exercise classes, the authors added.

More information

The U.S. Office of Disease Prevention and Health Promotion offers advice on keeping children at a healthy weight.