NIH-Funded Study Suggests Teen Girls Who Stay Up Late More Likely to Gain Weight

A new study has found that teenage girls who prefer to go to bed later are more likely to gain weight compared to same-age girls who go to bed earlier.

In a study funded by the National Institute of Health (NIH), 804 adolescents from ages 11-16 participated. 418 girls and 386 boys responded to questionnaires about their sleep habits, as well as wearing an actigraph, which is a wrist device that tracks movement.

Researchers then measured each participant’s waist size and calculated the proportion of body fat using a technique called dual-energy x-ray absorptiometry. They also estimated the children’s social jet lag, analyzing the difference between their weeknight and weekend bedtimes. Those who stayed up later on weekends than weeknights were considered to have a high social jet lag.

Specifically, for girls, staying up later was associated with an average .58 cm increase in waist size and a .16 kg/m2 increase in body fat. Each hour of social jet lag was associated with a 1.19 cm larger waist size and a 0.45 kg/m2 increase in body fat. Researchers statistically adjusted for other factors known to influence weight, such as sleep duration, diet, physical activity, and television viewing; these associations reduced, but still were present.

These associations were also found in boys, but the results were not statistically significant enough to report. The researchers concluded that improving sleep schedules may be helpful in preventing obesity in childhood and adolescence, especially in girls.

Reference

NIH-funded study suggests teen girl ‘night owls’ may be more likely to gain weight. NIH website. https://www.nih.gov/news-events/news-releases/nih-funded-study-suggests-teen-girl-night-owls-may-be-more-likely-gain-weight. Published September 16, 2019. Accessed September 16, 2019.