A great night of refreshing sleep is eluding most Americans. According to the National Sleep Foundation’s 2013 International Bedroom Poll 56 percent of people between the ages of 25 and 55 get an insufficient amount of sleep on workdays. On non-workdays individuals are then more likely to oversleep. They spend an additional 45 minutes catching Z’s in an attempt to compensate for accrued workweek sleep debt. Why are we constantly playing sleep-catch up during free time? As a society we are socially jet lagged. Social jet lag is the difference between sleep patterns on work days and free days.
These inconsistent sleeping habits result in sleep loss that is reminiscent of flying west across several time zones every Friday evening and traveling back East come Monday morning. The pattern reveals a critical disparity between society-imposed obligations, like work and family commitments, and our innate biological clock. Social jet lag might not sound like a big deal. What’s an hour or two of sleep lost here and there? But the chronic misalignment between our social and biological clocks is wreaking havoc on our health. Large-scale epidemiological studies have pointed a finger at short sleep duration for it’s causative role in the nationwide obesity crisis.
When you get too little sleep, normal levels of appetite hormones are altered in a way that could lead to increased food consumption and weight gain. Unfortunately for people struggling with social jet lag, short sleep duration comes with the territory of the workweek.
Some data even suggest that for every hour the biological clock is offset from the social clock, the chances of being overweight shoot-up by a whopping 33 percent. And supersizing the body mass index isn’t the only problem. Social jet lag has also been linked to the increased likelihood of nicotine and alcohol use, which independently contribute to additional health problems. The social jet lag epidemic tends to hit teenagers particularly hard. Their biology hardwires a preference for late night schedules that clash with early school start times.
A recent study published in the Journal of Developmental & Behavioral Pediatrics suggests that starting school a mere 25 minutes later can significantly improve adolescents’ mood and sleep duration while reducing caffeine use and daytime sleepiness. Many states have already begun championing delayed high school start times and some districts have reported declines in teen driver crash rates following new schedule implementation.
If the number of hours spent snoozing each day is critical for a healthy lifestyle, is society cheating more than half of Americans out of essential sleep with an unsustainable social schedule? For the more than half of Americans experiencing social jet lag, the answer is a resounding yes. But what about the other 44 percent? Why do some people thrive off of early morning schedules or late night shift work while others flounder? Whether you’re a morning lark, a night owl, or something in between, it’s a matter determined by a complex milieu of biological and social factors that involve subtle differences in biological clock genes.