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.

More: 9 Weird Things Killing Your Gut

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 The Supplement Handbook. First, forget the sleeping pills. "While these medications do cause drowsiness, they don't necessarily promote deep sleep or improve the quality of sleep," he says. 

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:

1. Melatonin

Dr. Moyad says taking 0.5 to 5 milligrams before bedtime can help you sleep better until you adapt. While your brain makes the melatonin hormone naturally to help you sleep, there are plenty of factors that can throw off your natural production. 

"[When it comes to jet lag,] timing is critical," says Dr. Moyad of taking melatonin for jet lag. "If you take it too early, you'll fall asleep too early and delay your adjustment to local time. Take it at bedtime every night until you adjust to the new time zone."

More: 15 Relaxing Things You Should Do Before Bed

While you shouldn't take melatonin more than you need to (as it is possible to develop a tolerance to it), it's safe to use melatonin to proactively avoid jet lag. By taking a dose of melatonin at your projected bedtime in the new time zone, your body can get a head start on adjusting. 

Traveling with your family? Three to 5 milligrams before bed is a safe dose for kids, but keep in mind that your kid may need less.

A few tips on buying melatonin supplements: "Don't be lured by pricey combination products," he says. "So many companies combine it with two or more ingredients and claim that it works better than melatonin by itself. Don't fall for it!"

Talk to your doctor about melatonin if you're on antihypertensive mediation, are on warfarin, or have epilepsy. 

2. Limit the alcohol

Maybe enjoy the big Thanksgiving game without a beer (or with fewer beers) this year. "It might make you drowsy," says Dr. Moyad, "but alcohol reduces deep and refreshing sleep and even REM (dream) stage." He also points out that drinking can lead to fragmented sleep (even if you don't notice it) and more disruptions due to nighttime bathroom breaks.

3. Ease up on caffeine in the evening

"Caffeine stays in the body (in large amounts) for about five to six hours," explains Dr. Moyad. "So if you're reaching for a java jolt between 4 p.m. to 6 p.m. or later, you may still be feeling the effects at midnight."

More: 6 Things You Should Never Do Before Bed

4. Keep cool

A cool temperature is one of the body's triggers for sleep, explains Dr. Moyad. Fortunately for you, it's winter so all you have to do is crack a window and let the sleep breeze in.

More: 50 Ways to Sleep Better Tonight

5. Sign up for a 5K or other exercise

Dr. Moyad says that having a regular exercise routine is a great way to help you fall asleep at the end of the day. In fact, studies have shown that any kind of exercise, whether it's intense or gentle (like restorative yoga), can have a beneficial effect. 

6. Unplug

Calming down your brain with acupressure or meditation can help with turning off a restless brain. Try these calm-down drinks to help you relax, naturally. And be sure to turn off your phone several hours before bedtime, since the light from electronics can mess with your sleep cycle.

7. Don't waste your time (or money) with...

Kava or kava kava. This antianxiety supplement is getting a reputation for damaging the liver. Dr. Moyad says it's not worth it, considering there are safer options. Other supplements Dr. Moyad suggests avoiding are passionflower, hops, wild lettuce, Jamaican dogwood, California poppy, and skullcap because there is a lack of scientific evidence that they're effective, despite the marketing claims.

This article originally appeared on RodaleWellness.com.