Why Your Late Bedtime Could Be Hurting You More Than You Realise

If you’re anything like the night owl I am, when the clock strikes 10pm, you’ll be feeling energised, pumped and ready for a productive “night” ahead.

And you’re not alone. As a generation, longer work days and 24/7 Wi-Fi connections mean we’re crawling into bed quite late. A study of the sleeping patterns of tens of thousands of US students in more than 100 universities by Jawbone, a company that specialises in fitness trackers, revealed that on weekdays the average bedtime for men was 1:02am, while on weekends it was 1:43am. (Women got to bed slightly earlier on weekdays, at 12:23am, and weekends, at 1:01am.)

But regardless of our mothers’ constant nagging for us to sleep earlier, there are many scientifically proven reasons why an earlier bedtime is better for us.

How your bedtime affects your weight.

Firstly, it turns out insufficient sleep has been linked to weight gain, as it both reduces your body’s ability to burn calories during the day, as well as causes a shift in hormone production, resulting in the production of more of the hormones that increase appetite and less of those that signal fullness.

However, your late bedtime may also be the reason your diet is not resulting in the outcome you were looking for. One reason is simply because those who sleep later generally get less sleep as those who go to bed earlier (because most of us still have to get up at the same time for school or work in the morning).

Another reason is revealed in a study by Northwestern University in Chicago, which found that those who slept later and consequently woke later tended to have their meal times later than early sleepers, and as a result, consumed significantly more calories after 8pm.

Late night snacking is strongly correlated with a higher BMI, as lower activity levels at night mean you’re burning off less calories lying in bed than you would walking around, which just means potentially more sugar is stored as fat.

How your bedtime affects the quality of your sleep (no matter the duration).

The time at which we go to bed can affect our quality of sleep, regardless of how much we end up getting (i.e. how late we get up), according to Dr. Matt Walker, Head of the Sleep and Neuroimaging lab at the University of California, Berkeley.

Put simply, your sleep in the earlier part of the night is dominated by non-REM sleep, which is deeper and more restorative than REM sleep, which generally kicks in during the early hours of the morning, no matter when you actually went to sleep. This is the main reason why when you sleep at 2am, you can get a full nine hours of sleep and still feel groggy.

Okay. So, now what?

As it turns out, our mothers were right all along, and that our bedtimes can have a very large impact on our health. A study by Baylor University in Texas even found skimping on sleep and then making up for it with long sleeps accelerates cognitive decline in young adults. For reasons such as these, shift work that disrupts the body’s natural circadian rhythm is considered a potential carcinogen by the WHO.

Resetting your body clock takes time, (no pun intended), but the benefits mean it might be a very good idea to change from a night owl to an early bird, as soon as possible.

Vivian Chen is one of Student Edge’s student contributors. See more student contributions here.

Photo: Comedy Central