During flight, I personally prefer to stay hydrated and fast. By fasting, not only will you reduce the amount of stress put on your body (remember that sitting for long periods of time, the dramatic change of pressure or crossing multiple time zones are all considered stress) – but it can drastically reduce jet lag symptoms as well!
By fasting, not only will you reduce physical stress – but you can have an easier time syncing both internal/external clocks (which will help regulate your hormones, digestion, blood pressure etc) by simply just waiting to eat shortly after landing based on local time.
During flight, I make sure to get up and walk around/stretch at the back of the plane (calf raises are a personal fav haha). I also put my feet on the metal frame below me while I’m seated. It sounds weird but by doing this, it can help ground you to the airplane frame. This will allow you to discharge excess positive charges you are accumulating during flight, inevitably thinning your blood and decreasing inflammation from flight.