Media Advisory

Monday September 16, 2019

What

A study funded by the National Institutes of Health suggests that adolescent girls – but not boys – who prefer to go to bed later have more weight, compared to girls of the same age who go to bed earlier. The findings of Kaiser Permanente researchers in Oakland, California, and other institutions are emerging in JAMA Pediatrics.

A total of 804 adolescents (418 girls and 386 boys) aged 11 to 16 years participated in the study. The children answered questionnaires about their sleep patterns and wore an actigraphe – a wrist device to track movements. The researchers measured waist circumference and calculated the proportion of body fat using a technique called dual energy x-ray absorptiometry. They also estimated the social jetlag of children – the difference between bedtime and weekend nights. Those who stayed up much later than weekday evenings were considered to have a high social time difference. The authors noted that previous studies had shown that adults who preferred to stay awake and had a high social time difference were more likely to gain weight than those who would be earlier and who had not. no social time difference. The researchers undertook the present study to determine if the same associations would be observed in young people.

For girls, staying up later was associated with an average increase in waist circumference of 0.58 cm and an increase of 0.16 kg / m2 increased body fat. Each hour of time difference corresponds to a waste size greater than 1.19 cm and a load of 0.45 kg / m2 increased body fat. These associations were reduced – but still remain – after statistical adjustment of the researchers to account for other factors known to influence weight, such as sleep duration, diet, physical activity and listening to television. Although researchers found slight associations between these measures and waist circumference and body fat in boys, they were not statistically significant. The researchers concluded that improving sleep schedules can be helpful in preventing obesity in children and adolescents, especially among girls.

Funding was provided by NIH Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institute of Diabetes and Digestive and Kidney Diseases, National Cancer Institute and National Institute of Heart, Lung and Blood.

who

Andrew Bremer, M.D., Ph.D., Head of the NICHD Pediatric Growth and Nutrition Division and who oversaw the funding of the study, is available for comment.

article

Cespedes Feliciano EM, et al. Chronotype, jet lag and cardiometabolic risk factors in early adolescence. JAMA Pediatrics. 2019

About Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD): NICHD conducts and supports research in the United States and around the world on fetal, infant and child development; maternal, child and family health; reproductive biology and population problems; and medical rehabilitation. For more information, visit the NICHD website.

About the National Institutes of Health (NIH):
The NIH, the country's medical research agency, has 27 institutes and centers and is part of the US Department of Health and Human Services. NIH is the lead federal agency that leads and supports basic, clinical and translational medical research. She studies causes, treatments and cures for common and rare diseases. For more information on NIH and its programs, visit www.nih.gov.

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