Teen Girl ‘Night Owls’ May Be More Likely to Gain Weight

A girl up late, reading a book.

Teen girls who go to bed later are more likely to gain weight, compared to same-age girls who go to bed earlier, suggests an NIH-funded study.

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Teen girls—but not boys—who prefer to go to bed later are more likely to gain weight, compared to same-age girls who go to bed earlier, suggests a study funded by NIH. The findings by researchers at Kaiser Permanente and other institutions appear in JAMA Pediatrics.

A total of 804 adolescents (418 girls and 386 boys) ages 11 to 16 took part in the study. The children responded to questionnaires on their sleep habits and wore an actigraph—a wrist device that tracks movement. Researchers measured their waist size and calculated their proportion of body fat using a technique called dual-energy x-ray absorptiometry. They also estimated the children’s social jet lag—the difference between their weeknight and weekend bedtimes. Those who stayed up far later on weekends than weeknights were considered to have high social jet lag.

The authors noted that previous studies had found that adults who preferred to stay up late and had high social jet lag were more likely to gain weight than those who went to bed earlier and did not have social jet lag. Researchers undertook the current study to determine if the same associations would be seen in young people.

Study funding was provided by NICHD, NIDDK, NCI and NHLBI.