STUDY: Does Jet Lag Cause Weight Gain?
Jet lag is the worst. It makes you miserable and sleepy for days, and can often make you miss out on some of the best parts of vacation. And now, to add to the grumpiness, a recent study has found that jet lag can contribute to obesity.
The study, published in Cell, studied the gut microbiome and how it is affected by a disrupted circadian rhythm. We recently discussed circadian rhythm in its relationship to sunshine. To maintain a normal circadian rhythm, spending time outside in daylight is vital. Ensuring your body clock is in sync is important so that your body is more willing to sleep when you need it to. The National Institute of General Medical Sciences states that the body’s master clock, or SCN controls your production of melatonin, the hormone that makes you sleepy. So, when your body’s master clock is off, it affects the way you sleep (hence jet lag) and now, it is proven to affect your body’s weight gain, too.
The study, led by Eran Elinav, MD, PhD, tested in mice the body’s reaction to disrupted circadian rhythms via jet lag. It found in mice that being jet lagged caused them to perform tasks at lower levels and they became more susceptible to obesity and diabetes.
When researchers transferred the gut bacteria of the jet lagged mice to sterile mice, they also received a heightened risk of disease. This proved that gut microbes are what are causing the problems.
While difficult to complete this study on a number of humans, Elinav did test the theory on two human subjects traveling from U.S. to Israel. After sampling their gut bacteria it was found that they also changed in composition similar to the change of the jet lagged mice.
It was found that after about two weeks the gut microbes returned to normal. But the findings are troublesome for frequent travelers or night shift workers who are constantly disrupting their circadian rhythms. The implications of higher risks of obesity and diabetes could be dangerous, and the study hopes to further the discussion into finding new ways that people with irregular schedules can stay healthy.