Looking at all the research, there appears to be only one real way to avoid jet lag: make your internal body clock adjust to the new time zone. And the key to achieving that is an understanding of how light influences your body clock.
There are several actions you can take before, during your flight and on arrival to help ‘force’ your body clock to change. Taking positive action may well reduce the severity of jet leg, as well as the length of time you experience it.
It’s important to recognize the difference between travel fatigue and jet lag, especially as the overall symptoms may feel the same.
General travel fatigue can be overcome relatively quickly, maybe after a rest and a night’s sleep. Jet lag tiredness, however, may well stay with you for much longer – until your body clock adjusts to the new time zone.
Shifting your time clock, with controlled exposure to strong light, is the best way to avoid jet lag. Or at least minimize the length of time you suffer from it.
If the time change is less than three hours and it’s a short trip, then you may be better off not trying to adjust to the new time zone at all.
Instead just keep close to your normal sleep schedule. Or if there’s more than 3 hours time difference, then perhaps just change your sleep times slightly.
By adjusting your sleep times and exposure to light, you should be able to adjust your internal body clock towards the new time zone before you leave.
This will reduce the length of time you suffer from jet lag on arrival at your destination. Of course, it may be easier said than done, as changing your sleep routine could be difficult for personal, social or work reasons.
The attraction is that this approach might allow you to arrive in your destination virtually jet lag free.
The advice from websites and online calculators is really based on the average person.
If the time zone change is greater than about 8 hours or natural sleep cycle is much later (real night owls) or much earlier (very early birds) it might be easier to start adjusting their body clocks in different directions.
The above calculator appears to be very close to the research based solution. It is an example only.
Disclaimer: This website is not a substitute for medical advice. Use at your own risk and consult with your physician.