Manny peoples agree with me on this score, but I’ve yet to find an explanation. Why is it that jet lag seems to be worse flying east?
Cecil’s archives yielded nothing. I did find this thread,but it really did not address the question. And I’ve found a few sites that address dealing with jet lag, some of which mention that flying east seems give rise to worse jet lag, but no explanations.
When you travel from CA to NY you end up having to get up three hours earlier. When you go from NY to CA you get to sleep in for three hours.
Which seems worse to you?
The simplest “explanation” is that when you travel east, you’ll be getting up earlier than your body clock is set for. For some reason, we humans think it’s easier to get up late than it is to get up early. 
Obviously, there’s more to it than that.
Having done it a few times, I think it’s mainly loss of sleep going eastbound. But don’t forget the possible contribution of drinking all that free airline-provided alcohol, at low cabin pressure (i.e. high cabin altitude) on an international flight, or up front in the Capitalist Pigs section. Losing sleep is bad enough, but losing it with a hangover too is worse.
This phenomenon was well known during the 1800s as well. No one ever said “Go east, young man”. Coincidence? I don’t think so.
beatle
I can see from this thread why the “sleep late” argument doesn’t work for you. Well, jet lag doesn’t affect everybody, either.
Sorry, flying west is the killer for me… longer day? I don’t know however I think part of it is just sitting in a small tube with lots of other bored folks. I get just as bored on a 10 hours+ flight east-west and north-south.
Frequent traveler checking in. Yes indeed, going east is much worse for me.
When I cross the Atlantic westbound, the day I travel is a few hours longer. For my body it means staying up late and it does not have too much problem with that. Imagine you stay up late a few days in a row. You soon get used to getting up later in the morning. No big deal.
Now, do the opposite. When I cross the Atlantic going to Europe, the day i travel, when it is bedtime there my body says it is 4PM. Well, I don’t care what, I am not sleepy. So I stay up all night. Which means either I sleep half of the next day or I am dragging myself. This goes on for several days. Finally I force myself not to sleep during the day. For a couple of days I manage it and i think my body has fallen in line. Nope! Suddenly it will go back to feeling tired during the day… I can go for a week or two before I become half adjusted.
I have probably crossed the Atlantic more than 50 times… it is always the same.
(I am not even going to talk traveling to China which is 12 hr difference - that really messes you up)