Bad news for night owls: late sleepers are more likely to gain weight

    2 October 2015

    People who go to bed late are more likely to gain weight, according to a study by researchers at the University of California and published in the journal Sleep.

    The study looked at the sleeping patterns and lifestyles of 3,300 young people and adults, and found that for every hour that sleep was delayed they gained 2.1 points on the body mass index (BMI).

    Interestingly, the number of hours slept had no impact on BMI. The amount of exercise and time spent exercising didn’t have an effect either.

    Lauren Asarnow, the study’s lead author, said: ‘These results highlight adolescent bedtimes, not just total sleep time, as a potential target for weight management during the transition to adulthood.’

    The researchers looked at data from the National Longitudinal Study of Adolescent Health, which has tracked the behaviour of American teenagers for over 20 years.

    The research also showed that many teenagers don’t get enough sleep at night, and report having trouble staying awake at school.

    The latest study suggests that adolescents who go to bed earlier will ‘set their weight on a healthier course as they emerge into adulthood’, Asarnow said.

    According to the Great British Sleep Survey, carried out in 2012, poor sleepers are three times more likely to struggle with concentration, and twice as likely to suffer from low moods and relationship problems. The survey also found that women, on average, don’t sleep as well as men, and that sleep quality decreases as we get older.