Looking For A Way to Fight Jet Lag? Try Starvation.

According to a Harvard Medical School study that appears in the journal Science, fasting before a long flight can help prevent jet lag. (Insert joke about airlines cutting meal service here.)

The body’s natural circadian rhythms serve as the clock that tells us when to wake and when to sleep. Jet lag happens because this clock is only capable of shifting slowly, and can’t keep up with major time-zone changes. "It takes the average person about a week to adjust to the new schedule," says Clifford Saper, the doctor who led the study.

Researchers already knew that hungry animals override their normal clock to improve their chances of finding dinner, but they weren’t sure why. Conducting tests on genetically engineered mice, they found that while the body’s normal clock is powered by reaction to light, there is a second clock that organizes sleeping and waking schedules around eating.

When the body feels its moving into starvation mode, this second clock kicks in, adjusting sleep schedules to maximize the chance of finding some grub. "A period of fasting with no food at all for about 16 hours is enough to engage this new clock," Saper says.

While there’s no conclusive evidence that someone who doesn’t eat for a day will walk off their 16-hour flight rested and relaxed, Saper said in an interview that he’s going to try it next time he flies to Japan.