Jul 03, 2013

    Night owls risk having expanding waistlines

    STAYING up late not only affects your alertness the next day, but it will also make you thicker in the waist.

    Researchers at the University of Pennsylvania in the United States found that study subjects who were kept up until 4am in a sleep lab ate more than 550 extra calories during the late-night hours.

    This is because people tend to crave junk food in the wee hours of the morning.

    While prior research has associated sleep deprivation with increased snacking, this study adds to the mounting evidence that seven or eight hours of sleep does a body good, while also providing insights from a lab setting.

    The randomised study, involving 225 healthy adults, found that people who spent only four hours in bed from 4am to 8am for five consecutive nights gained more weight than control subjects who slept 10 hours each night from 10pm to 8am.

    The sleep-deprived subjects not only consumed more calories, but they also ate more fatty foods during the late-night hours than at other times of the day.

    The study also found that men gained more weight than women if they stayed up late.

    The study appears online in the journal Sleep.

    A separate study published earlier this year also finds that sleeping a mere five hours a night during a workweek with unlimited access to snacks is not good for the waistline.

    The study, led by the University of Colorado at Boulder, found that participants gained nearly 1kg in five days when put in such a situation.