Going to bed too late during a work week is associated with weight gain in adolescents. This would not be offset by the total duration of sleep.
In adolescence, going to bed too late during a school week is associated with an increase in body mass index (BMI), suggests a american study published in the journal Sleep.
This work, carried out with more than 3,300 adolescents over 15 years, shows that delaying your bedtime by an hour is associated with an increase in BMI of 2 kg / m2.
In addition, the researchers were amazed to observe that total sleep time, regular physical exercise, or time spent in front of screens did not change this relationship. Sleeping in on the weekend would therefore not protect extra pounds.
A disrupted biological rhythm
“These results are important because they highlight that bedtime in adolescents, and not just total sleep time, is a potential target for controlling weight gain in adolescence and during the transition to adulthood. », Says Lauren Asarnow, author of the study and doctoral student at the University of Berkeley (California).
If bedtime plays a role in the development of overweight, or even obesity, we can assume the same for waking time. In fact, last August, a US government report showed that middle school and high school students were not getting enough sleep because school started too early. “Whatever the reason, they choose to start high school very early, which really contradicts the biological rhythm of high school students,” lamented at the time Anne Wheaton, epidemiologist in the public health division at the Centers for Disease Control.
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