Holidays are a double whammy when it comes to gaining weight. Not only do many of us overdo it in the calorie department this time of year, but now Israeli researchers have also uncovered another potential cause of holiday-related weight gain: the jet lag you suffer while traveling.
So how exactly are a growing belly and your red-eye flight to visit your aunt across the country connected? Your gut bacteria.
You know how jet lag prompts your body to feel like it's 6 a.m. even when the clock says it's noon? That travel-related clock chaos is throwing off your gut bacteria, too. And that impacts a lot, considering researchers are now calling the gut the "second brain" because it regulates everything from mood to weight and weight-related issues.
According to the researchers, disrupting your natural circadian clock (through both changing light-dark cues and altered eating habits) also changes the rhythms and compositions of your gut bacteria.
The researchers first tested their theory on mice and found that disrupting the mice's microbiomes by inducing jet lag led to weight gain and diabetes-like metabolic issues in the animals. These findings were echoed in a case study of two jet-lagged humans making the trek from the U.S. to Isreal. The researchers found that the humans' gut microbiome had shifted to favor the growth of bacteria that have previously been associated with weight gain.
"These findings provide an explanation for a long-standing and mysterious observation that people with chronically disturbed day-night cycles due to repetitive jet lag or shift work have a tendency to develop obesity and other metabolic complications," says Eran Elinav, MD, researcher with the Weizmann Institute of Science.
Fortunately, there are easy ways to get over jet lag quickly, says Mark Moyad, MD, MPH, author of
Also, keep in mind that not all jet lag is created equal. "Flying east is usually worse because you lose time," he says. "Going from Michigan to Europe or the Middle East, you lose five to eight hours, which means bowel habits, meals, and other daily rituals get thrown off. Flying west, you gain time, so it is usually easier to adjust because there's still time during the day for your body to take care of its normal rituals."
Here, we have Dr. Moyad's seven tricks to get over jet lag faster: