If you’ve ever felt hungrier on a plane, train or road trip, you’re not imagining it — research shows travel can alter healthy eating habits. A study published in the Journal of Occupational and Environmental Medicine found that, compared to homebodies, frequent travelers had a greater risk of obesity and higher blood pressure. And another recent study found that those who spent more than 14 nights away from home each month had a higher BMI; the odds of being obese were 92% higher among those who traveled more than 21 nights per month.

Here are three reasons travel might leave you reaching for less-healthy food options and what to do about it:

1.  THE CHANGE IN TIME ZONE

Jet lag disrupts ghrelin, the hormone that increases appetite, and leptin, the hormone that decreases appetite, according to 2017 research. If you’re crossing time zones, you may end up eating more frequently or craving high-calorie foods.

“The impact that moving between time zones has on our sleep-wake patterns can also change the timing of our hunger cues,” says Alissa Rumsey, RD, a certified strength and conditioning specialist and New York City-based nutritionist. “And if you’re not getting enough sleep, your cortisol levels can rise, which can also increase your appetite.”

The fix: Try to eat meals at the proper meal times in your new time zone, which helps reset your internal clock. Rumsey also suggests honoring your internal hunger signals: “Our bodies are smart and will cue us to make sure that we eat when we need fuel.”

2.  YOU’RE DEHYDRATED

It’s not surprising you feel parched on the plane. The humidity in the cabin can be as low as 10%, making you feel dehydrated — and that can increase your appetite.