Fasting to Mitigate Jet Lag: Surprise! It Works!

I’m a frequent traveler, and thus a frequently suffer from moderate jet lag. It’s just so hard to adjust to a new time zone! But I recently stumbled on a simple method many claim helps your internal clock re-calibrate to travel. After trying it out on my trip to Australia last week, I’m convinced it can help!

On the Nature and Cause of Jet Lag

Jet Lag is pretty simple: One’s internal “clock” becomes out of sync with local time when one travels rapidly from West to East. This causes inappropriate sleepiness and wakefulness, indigestion, and trouble with concentration and cognition. In other words, Jet lagged people are tired, sour, and confused.

The cause is simple to understand. Our bodies have evolved an internal “clock” to allow us to function on this planet. We follow a cycle of waking, eating, working, and resting over the 24 hour period of the day.

If we didn’t have this internal clock, daily life would be pretty bizarre: We would sleep when we were tired and eat when we were hungry regardless of daylight or the activities of others. This sort of non-schedule would certainly have interfered with our success as a species, so it’s no surprise that most creatures on earth follow a daily schedule synchronized to the turning of the planet!

Rapidly traveling East or West puts our bodies out of sync with the “natural” daylight-driven pattern of life where we land. We get hungry and tired at the wrong time, but forcing ourselves to adjust rarely works: We can’t sleep at night but fall asleep during the day; we wake up starving but peck at dinner.

Note that jet lag is different from the natural fatigue of travel. Many people (including me) don’t sleep easily on planes, and the stress of airports, taxis, and tickets causes many symptoms similar to jet lag. But fatigue is easily remedied with a good night’s sleep, while true jet lag often takes days or weeks to vanish.

This phenomenon was rare before the jet age because we couldn’t actually travel all that rapidly: Horses, ships, and trains are slow enough (and stop frequently enough) for us to adjust to the local time without much trouble. But, as I recently experienced, a jet can transport you across a dozen timezones in less than a single day!

Adjusting the Body’s Clock

Science tells us it takes a day or so to adjust to a one-hour difference in time, but many frequent travelers seek a quicker remedy. After all, no one wants to spend a week or two adjusting, especially if business, politics, or war demands our skills!

The body expects about 12 hours from dinner through night to breakfast, and it is very difficult for the body to “compress” time – digestion can’t easily be sped up, and it’s very challenging to sleep when not tired. Yet travelers try to do exactly this when they travel: They eat dinner after takeoff in New York and breakfast five hours later as they near London. No wonder the body can’t adapt!

It’s even worse on longer flights, where everyone is roused by an extra meal half-way through. Airlines keep to this bizarre schedule because travelers would rebel if they were left without food for six, ten, or even twenty hours. But it actually contributes to worse jet lag, since the body becomes “confused” about the time even while en-route.

Many people suggest sleep or exercise as a jet lag cure, and I don’t doubt that these can help. A nap definitely helps with alertness, and exercise can cue rest. But these appear to treat the symptom rather than the problem: The body is still out of sync, it’s just not quite so tired. Stimulants and sedatives similarly treat the symptom not the underlying disorder.

Exposure to daylight is another common suggestion with some merit. It is known that sunlight stimulates the brain, and it is logical that this would help calibrate the body’s internal clock. I always let the sun shine into my hotel room to help me wake at the right time when traveling rather than relying on an alarm clock.

Fasting to Reset the Clock

Although it is difficult to “compress” the body’s clock, it may be possible to “elongate” it. This is the theory behind a novel treatment for jet lag. By stretching a single day to 30 or even 36 hours, one can more easily adapt to a new time zone. But how do you pause your internal clock?

Studies in mice have shown that fasting can cause bodily functions to slow to a crawl, yet the metabolism can quickly rebound when food is consumed again. Some have attempted to use this to fight the effects of aging, but it is probably more useful when applied to shorter-term problems like jet lag.

By avoiding all food, the body’s internal sense of time is compressed and a longer day becomes possible. Then, by eating a large breakfast to start a new day, the body is jolted back into action in a completely new time zone!

This jet lag treatment originally included a week of alternating “feast and famine” days to “prime” the body for the big pause. Apparently, Ronald Reagan was a big advocate of this concept, as is the US military. But other studies have shown that even a single fast can do the trick.

Experimenting on Myself: Ohio to Australia and Back

I decided to give the fasting trick a try on my recent trip to Sydney and Melbourne to give the keynote speeches at their VMware User Conference events. I wanted to be alert, not just for the conference but also an exciting overseas visit! But I was deeply concerned about the effect a trip across the International Date Line and an eight-hour time difference.

I decided to try a simple version of the fasting trick: No food from dinner local time to breakfast on arrival. For the trip out (a Friday afternoon-to-Sunday morning flight) this meant nothing to eat from dinner Thursday in Ohio to breakfast Sunday in Sydney, a span of about 30 hours. On the way home, I ate dinner in Sydney on Friday and breakfast about 32 hours later on Saturday morning in Ohio.

To avoid fatigue, headache, and altitude issues, I drank plenty of clear liquids, including my favorite Vitamin Water Zero, seltzer water, ginger ale, and plain water. Apart from the sugar in these beverages, my body had no calories or bulk to digest.

I was shocked at how easy it was to fast for this amount of time. Although I felt like I should be eating, I didn’t really feel hungry. The excitement of travel probably played a part, as did the lack of appetizing vegetarian food selections on United Airlines. But on the whole, fasting for the trip was really quite simple.

Amazingly, it worked! I tried to sleep on the plane, since I would land in the morning local time, but this is not easy for me. Nonetheless, I arrived feeling tired and dried out but fully alert and ready for a day of sightseeing with a local friend. This despite the fact that the day started at 11 PM Ohio time! I was sleepy that night, but not overly so, and had no trouble waking in the morning.

The whole trip was fantastic, and the return was just as easy. Tired from the flight (I stayed awake the whole time, treating it like a very long day) I had no trouble sleeping and was only moderately hungry in the morning. I did feel a bit laggy, it was more like a 2-hour difference from Mountain time than the 8-hour Eastern Australian zone.

Stephen’s Stance

Fasting appears to be an easy and effective method of stretching the body’s cycle to match local time, and a big breakfast is a great way to kick off a new day in a new city! I’m not sure I would bother going through all this for short US trips, but I will definitely recommend it for long international journeys. Considering the “cost” of skipping a few tasteless airline meals, I’d say it’s well worth the effort!