Social Jetlag Contributes to Obesity

Social jetlag — a syndrome related to the mismatch between the body’s internal clock and the realities of our daily lives — is a contributing factor in the growing obesity epidemic, according to a new study.

“We have identified a syndrome in modern society that has not been recognized until recently,” said Till Roenneberg of the University of Munich. “It concerns an increasing discrepancy between the daily timing of the physiological clock and the social clock. As a result of this social jetlag, people are chronically sleep-deprived. They are also more likely to smoke and drink more alcohol and caffeine. Now, we show that social jetlag also contributes to obesity — the plot that social jetlag is really bad for our health is thickening.”

Each of us has a biological clock, he said, adding that those clocks are regulated by daylight and darkness to provide the optimal window for sleep and waking. In modern society, however, we listen to those clocks “less and less due to the increasing discrepancy between what the body clock tells us and what the boss tells us,” he said.

Roenneberg’s team is compiling a database on human sleeping and waking behavior, which they plan to eventually use to produce a world sleep map. Now 10 years into the effort, they have compiled lots of information, including participants’ height, weight, and sleep patterns.

Their analysis shows that people with more severe social jetlag are also more likely to be overweight.

The findings should factor into decisions about Daylight Saving Time, as well as work and school times, the researchers said. It would also help if people began spending more time outdoors in open daylight or at least sitting by a window, they add. As people fail to do this, their body clocks get set later and later, leaving them awake into the night and tired by day.

“Waking up with an alarm clock is a relatively new facet of our lives,” Roenneberg says. “It simply means that we haven’t slept enough and this is the reason why we are chronically tired. Good sleep and enough sleep is not a waste of time but a guarantee for better work performance and more fun with friends and family during off-work times.”

Source: NST 13th May 2012