In the battle against childhood obesity, a new cause has emerged: isolation. Researchers say kids who feel left out, even briefly, may be less active overall.

The results of a new study — the first to measure the effects of ostracism on the physical activity of children — showed that kids who were excluded during an online computer game later spent 41 percent more minutes engaged in sedentary activities like drawing, crossword puzzles or reading instead of opting from a choice of physical activities that included obstacle courses, jumping rope or shooting basketballs.

Since previous studies have shown ostracism increases eating, researchers say the results of the latest study point to yet another way that feeling shunned can lead to childhood obesity.

“These findings are worrisome,” wrote researcher Jacob E. Barkley, PhD, of Kent State University in Pediatrics. “[They] suggest that experiencing ostracism has an immediate negative impact on children’s choice to be physically active … The lack of physical activity and engagement in sedentary behaviors in children and adolescents are concurrently and prospectively related to obesity and other health difficulties.”