An example of how much our bodies are attuned to the Circadian rhythm is shown by the fact that research into the design of space stations has found that altering the lighting to mimic the daily cycle of light and dark, helps astronauts to adapt more easily to being up in space and away from the earth.
So is there anything at all that you can do to prevent jet lag? Well, some of the symptoms of jet lag can actually be caused by dehydration, so be sure to drink plenty of water when you are in the air. Also try not to overdo the coffee and alcohol over the course of long haul, as both of these dehydrate the body. I must admit though that this is easier said than done.
Another tip is that before your journey you start to try and think in terms of the time at your destination, and get earlier or later nights as necessary, in order to match the cycle of day and night at the place you are travelling to. However this idea may not be terribly feasible if you have a busy work schedule to keep to right up to the point of departure.
If you do end up getting jet lag, you will probably find that while you are trying to adapt to the new time zone at your destination you are feeling lively and awake when everyone else is going to bed, and that you are exhausted and sleepy when everyone else is getting up and going to work. Try to counteract this by taking some modest exercise, such as walking, during the day, as this will help you to sleep that bit better at night. Try to rest when you are fatigued, and bear in mind that after a few days you will be fully adapted to your new daily rhythm.