There is some controversy about that because every person is different. Some people try to preshift to the other time zone. If you are going to be gone for a long time, it makes sense to preshift. If you are on a short trip, it makes sense to stay in the current time zone. Other people try other things: bright lights, pharmaceuticals such as melatonin or Provigil, caffeine or naps. Directly or indirectly, these things are ultimately going to affect the brain's clock.
What do you advocate?
I try to stay in my own time zone when traveling within the U.S. My advice is work with your natural rhythm. There's a second thing I do. If you're going to travel to Europe, get up, start your sightseeing and engage in vigorous activity. Also, eat multiple small meals throughout the day. I feel less nauseous and more alert.
