A new study has revealed that sleeping late at night could lead to weight gain in teenagers and adults.
In the study, University of California researchers analysed longitudinal data from a nationally representative cohort of more than 3,300 youths and adults, and found that for every hour of sleep they lost, they gained 2.1 points on the BMI index. This gain occurred roughly over a five-year period.
In addition, exercise, screen time, and the number of hours they slept did not mitigate this BMI increase.
Lead author Lauren Asarnow said that these results highlighted adolescent bedtimes, not just total sleep time, as a potential target for weight management during the transition to adulthood.
The study focused on three time periods, the onset of puberty, the college-age years and young adulthood. Researchers then compared the bedtimes and BMI of teenagers from 1994 to 2009.
According to the study, adolescents reported their bedtimes and sleep hours while researchers calcu lated their BMI based on their height and weight.
Surveys reported that many teenagers do not get the recommended nine hours sleep a night, and report having trouble staying awake at school.
Asarnow said that the results of the study suggested that adolescents who go to bed earlier would set their weight on a healthier course as they emerged into adulthood.
The study is published in the Journal Sleep.