Since this came up in a course recently, apparently jet lag is (at least partially) caused by: 1. Your circadian rhythm [1] being out of sync. In a nutshell, a

Since this came up in a course recently, apparently jet lag is (at least partially) caused by: 1. Your circadian rhythm [1] being out of sync. In a nutshell, a reasonable amount of internal biology is synchronized to the time of day to improve efficiency. If your activity isn't in sync with what your 'internal clock' is expecting, you experience jet lag. 2. A limited ability for the clock to adjust to a new timezone. The direction of adjustment is encoded by a phase response curve [2] and is affected by exposure to light -- practically nothing else can shift it. 11thEarlOfMar has the right idea -- if you can avoid light exposure entirely, your clock won't shift and you won't be jetlagged. Otherwise, large doses of light at the right times of day are (apparently) the best cure. [1]: https://en.wikipedia.org/wiki/Circadian_rhythm#Humans https://en.wikipedia.org/wiki/Circadian_rhythm#Humans [2]:https://en.wikipedia.org/wiki/Phase_response_curve https://en.wikipedia.org/wiki/Phase_response_curve