Does Fasting Really Help Prevent Jet Lag?

There are many proposed ways to prevent jet lag. Among the suggestions are things like naturally changing your circadian rhythm clock over a few weeks by going to bed later or earlier than you would. In 2008, the idea of fasting to prevent jet lag was proposed, but don’t commit to starving yourself just yet.

The idea that fasting may prevent jet lag is based on studies done on mice. A study at Harvard Medical School does suggest we do have a second clock, one based on our waking to eat when there is normally the highest possibility of getting food. Scientists used mice which were genetically engineered to lack the gene responsible for governing circadian rhythm, and than gave them a gene in the form of a virus that knocked out their ability to use their “second” clock or food clock. Mice who received this extra gene would simply sleep through any possibility of getting a meal, and had to be woken and fed.

Doctors then restored the gene function of the “food clock” and the mice were readily able to accept their new schedule, and automatically begin to wake up about an hour before it was time to eat. From this study, doctors theorize that people may have a similar mechanism, which also influences jet lag. We may be waking up at the wrong time in a different time zone not just because we’re used to sleeping at different times, but also because our bodies are signaling us that it’s time to eat.

The theory that we can prevent jet lag by fasting comes from these mice studies. If we fast for 12 hours, supposedly, we reset our food clocks, which may help prevent jet lag. The only problem with this nicely put theory is that it doesn’t appear to work in humans. Similar studies on humans who fast for 12 hours before a flight or before working a graveyard shift show no reduction of jet lag symptoms or ability to sleep more easily on a different schedule.

There’s another problem inherent in this study. Fasting and flying may be difficult for some. People who suffer from low blood sugar could add pervasive nausea or vomiting to their jet lag symptoms. Dehydration might be an issue on hot days. Since this idea doesn’t seem to really work at resetting our clocks, you may want to investigate other methods for handling jet lag. Of course, mice are now able to prevent jet lag by a 12 hour fast. But are we men (or women) or mice?