How to Beat Jetlag by Fasting

by on June 14, 2012 · 19 comments

in TPG Contributors, Travel Health

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TPG contributor Katharine Gammon is a science writer for publications including WIRED, Popular Science and Los Angeles Magazine. When she’s not jetting to international conferences to interview some of the world’s leading scientific minds, she’s globetrotting herself, exploring unique destinations including recent trips to New Zealand and Southeast Asia. Today she writes about the science of jet lag and an innovative new method (with roots in human evolution) for combating it.

Summer is one of the most exciting travel seasons. But whether it’s lounging in sunny Mexico or exploring the Far East, travel comes with a not-so-pleasant side effect: jet lag.

Don’t start stocking up on the Ambien just yet, though. Clifford Saper of Harvard University’s Neuroscience Department may have found a way to speed up the body’s adjustment to a new time zone. It all has to do with circadian rhythms – those internal “clocks” in our brain, liver, heart and other tissues that regulate the body’s wakefulness, among other things. These circadian clocks are coordinated by a tiny cluster of cells in the brain called the pineal gland, which is highly sensitive to light and dark. When you move quickly across time zones, the body’s clock gets out of whack, making you feel zonked (the technical term, I swear) when you arrive at your destination.

Getting right to sleep on those long-haul flights can be key to avoiding jetlag once you arrive in your destination.

However, there is a cycle that’s even stronger than this light-based schedule enforcer. Saper had been working with animal sleep cycles, keeping nocturnal animals like rats active during the day. “Scientists have known since the 1920’s that if you took an animal and only allowed it to eat while it was supposed to be asleep, it would switch its cycle,” he explains. This makes sense for evolution – if an animal suddenly was faced with a shortage of its food, and needed to hunt during normal sleep hours, it would be beneficial to flip its schedule for survival.

His research led him to a particular hypothesis: If people also were to eat at the time that’s appropriate for the time in the place they plan to arrive instead of the place they’re leaving, they might also show this effect. For that to happen, he suggests that people fast while on the plane trip. “The thing about the feeding clock is that it supersedes the regular clock in the brain that is driven by light,” says Saper. “So the light cycle remains in the brain, but your body rhythms adjust immediately with the food cycle.”

So basically, by adjusting your eating cycle, you can reset your internal clock faster and more effectively than by adjusting your sleep cycles.

The Paris Paradigm
This is how it would work for a 7-hour flight from New York to Paris:

Fast after breakfast. Most Europe-bound flights are in the evening, so fasting during the day would help your body prepare for its new time zone. You need to fast for about 16 hours for the food-regulators to take over. Granted, a 16-hour fast is an extreme example, but hey, think of all those baguettes and café au laits you’ll enjoy in France once you arrive. Most of all, try not to get “hangry” before your flight because being polite with your other passengers and the flight crew goes a long way.

Avoid caffeine, alcohol or food on the flight. I know, it’s hard to turn away some champagne in business class or a gorgeous meal when you’re on a luxurious vacation. But fasting is the way to make your body reset. If you need to eat something, try to eat fruit and drink lots of water. And sleep as much as you can, Saper advises.

When you arrive at your destination, have breakfast at the appropriate time.  Most flights land in Europe in the morning, so have breakfast when it’s morning in France, and see if your body snaps into that time zone.

No one wants to miss out on their trip because of jetlag.

The Asia Axiom
It’s similar, but a little more complicated for a flight to Asia:

Fast during the day of your flight. You’d need to time your first meal to the morning in Tokyo. Say your flight departs at 3pm from New York (when it is 4am in Tokyo) and arrives at 4pm in Tokyo. To follow the plan, you’d need to fast during day in New York, then try to sleep the first few hours on the flight.

Avoid caffeine, alcohol and food on the flight – until the equivalent of breakfast time at your destination. Since most flights land in the afternoon Tokyo time, you need to have breakfast 6-8 hours ahead of landing. Saper suggests asking the flight attendants to hold your dinner and have it as your breakfast about 6-8 hours ahead of landing time.

Saper’s research on animals was published in 2008 in the journal Science. “It’s kind of interesting that there are hundreds of papers on the phenomenon in experimental animals, but not one in humans,” muses Saper.

Saper’s research does have some human-based precedents, though. Many travelers, including the military, follow the Argonne Anti-Jet-Lag Diet, which relies on a similar fasting and feeding program. Developed by a biologist at the Argonne National Laboratory outside Chicago, the diet alternates two days of moderate pre-departure feasting with two days of fasting — feast, fast, feast, fast — with the second fast on the travel day. A study of U.S. National Guard troops headed to or returning from South Korea showed that those who followed the diet experienced less jet lag than those who didn’t follow it.

As for artificial aids and alcohol, being in a plane is like being in a high mountain town, so alcohol can be particularly potent – and not helpful to recovering from jet lag. Ditto for sedatives and sleeping pills, which can foul up internal clocks and take longer to metabolize. Though fasting seems like it would be a pre-trip hardship, if you’re on a quick trip where you’re looking to make the most of your time on the ground, perhaps a little pre-journey abstention is worth not waking up at 4am and losing a day to grogginess.

Good luck traveling, and let us know if anyone has tried the fasting method!

Disclaimer: The responses below are not provided or commissioned by the bank advertiser. Responses have not been reviewed, approved or otherwise endorsed by the bank advertiser. It is not the bank advertiser's responsibility to ensure all posts and/or questions are answered.

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  • Jean-Maximilien Voisine

    This post is excellent with very nice advices ;)

  • D. Wang

    Thank you for this article. Very interesting.

    My personal experience in taking US-Asia flights is that when I had only vegetarian food onboard, the jetlag switch would be easier. Nowaways I always request vegetarian food whenever possible on a trans-pacific flight.

  • Jamie

    You don’t need to fast for redeyes to Europe. Just back up your meals.

    On the day I travel, I wake up around 4 AM and then immediately eat breakfast. At 10 AM I eat a light lunch. I get to the airport at 3 PM and immediately eat a big supper. I take a nyquil about 30 minutes before departure and when I get on the plane I tell the FA that I don’t want any food and that I don’t want to be disturbed. It works great for me.

    Part of the problem with supper in F is that it takes about 3 hours to do the whole thing. Even if you could immediately fall asleep, there are only about 4 hours left in the flight.

    The last time I didn’t do this was on an anniversary trip with my wife. She was very excited about the F meal and so I wanted her to experience that. I ended up with about 3 hours of sleep and was worthless the next day.

  • tivoboy

    Funny, my father actually pioneered much of this early research. It turns out that what is APPARENTLY partially driving the pineal to drive the phase shift are stimuli from the LIVER. It boils down more to WHAT one eats and at the appropriate time more than WHEN one eats. Of course the closer the timing is the better but think about WHAT one is eating. As an example, when we get to Europe, in the early AM, we start eating croissant and caffeine and orange juice. But, our stomach and body is still expecting something like a dinner meal, most likely NO caffeine, maybe a bit of alcohol and then something sweet. That sets up the process, but now the whole system is OFF. Digestion has changed dramatically which impacts a whole slew of endocrine system outputs, which then drive the activity in the brain. The more we can setup for the location based food consumption and timing, several days in advance, the better. When I head to Europe, I flip my eating 2-3 days prior. I have meats (mostly proteins) in the mornings at home and more carbs at night, then when I get to Europe my local consumption matches what my body has been experiencing already for several days. Obviously, the old tactics are still very good. get as much light in the morning at your destination as possible, get up early, stay up late, don’t go to bed at 4 in the afternoon as much as you can avoid it, etc. LIGHT is still the primary driver.

  • db

    My method is a bit simpler but equally effective and also takes into consideration that life is short:
    Get on your flight eat and drink a lot, pass out. next morning will be a bit rough.

  • Zz

    Sounds like an excellent approach when going in business class. Sadly sleeping in coach is just about impossible for a taller person.

  • Peach Front

    I wish somebody would force Saper to take a few dozen flights to Tokyo until the good doctor figured out why this advice is amazingly useless. Sheesh. That said, Delta more or less forced me to fast on my last flight JFK-KIX by 1) providing hardly any food, and 2) what little there was (not enough to keep a mouse alive) was not edible. So maybe Saper and Delta are working hand in hand to cure jet lag. But, honestly, go ahead and tell the crew to deliver your meal hours after everybody else and see how that works out for you. I’ll keep in mind that advice to avoid alcohol until it’s breakfast time though. There’s some news we can use.

  • Whiskarina

    I’m with DB… getting there is half the fun! =^..^=

  • Ram Kashyap

    Couple of things worked for me during my flights to India via Europe and Middle East. I would work super heavy and keep myself awake as long as possible for 36 hours before the flight like packing gifts, shopping for chocolates etc. I usually do not consume anything 6 hours before the flight (whatever time of the day it could be). Once I board the aircraft I drink plenty of water and sleep for couple of hours. I usually ask the crew to hold up my dinner if the flight took off after 8 PM. After I wake up I request a fruit and the drink some thing along with my food. This has worked for me several times. I have to be very energetic after travelling for almost 25 hours as I have to take a 12 hour train from the nearest airport to reach my parents’ home. So I have to beat the jet-lag to factor to enjoy a 3 week vacation and fit 50 hours of air time in that bracket.
    This article is really really great which combines a lot of cognizance on human clock cycles and how you could alter them taking examples like flights to Europe and Asia. I would love to see an example on flights to South Asia like India, Sri Lanka etc.

  • JF

    Thanks for the article. However, I don’t believe I’ll be able to fast on a flight.
    It’s on YT:

  • Dan C

    I do the opposite eat, eat & eat. Eventually I am eating at the correct time for the destination.

  • Anne

    I’m sure all of this is quite true, and perhaps very handy for the frequent business traveler. But for some of us vacationers, pleasure and indulgence is the name of the game when we travel.

    I want favorite foods, fine chocolates, and lots of great experiences on my trips. My trip experience starts with weeks of dreamy anticipation. I wouldn’t dream of going hungry for 6-16 hours beforehand.

    But that is only my take on life.

  • Ryan The Intern

    Sometimes its hard to resist all that business class food they keep serving!

  • Asen

    My method is even easier, get a night out the day before you travel. Normally this is easy because there is lot to do before a trip. Sleep the whole way on the plane.. When you arrive in Europe you would be refreshed..

  • MFK

    I have never tried fasting, and not sure I will or can, but I’m a firm believer in many of the other tips (e.g., no caffeine or alcohol, adjusting your sleep rhythms).

  • Yichuan

    I eat everything and drink alcohol to the point that I feel buzzed but I am sure I won’t have a headache tomorrow, and then I just pass out.

  • RakSiam

    This makes some sense for sure. I have been trying to figure out the best strategy for a trip to Asia. My flight is 16 hours. Leaves JFK in the morning and arrives HKG then TPE in the evening. I am thinking it makes sense to stay up the night before, try to sleep the first half of the flight, then get up , eat and stay awake. On arrival in TPE, have a light meal and go to bed at a more or less regular bed time. Get up the next day on schedule.

    I like to try and arrive in Asia in the evening (late evening in BKK for example) so I can just get to the hotel and go to sleep. That seems to work best for me. I have a hard time sleeping on planes though, even in F.


    Interesting ideas. I think there’s a good chance it would work, but having to fast during travel is just such a huge downside. I think I’m with Jamie. I’d be more likely to try to shift my meals, rather than doing a complete fast.

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