Long-haul flights are only good for two things (other than getting to the destination).
Free in-flight meals and in-flight movies.
After you've bingewatched the six-month-old blockbusters, you're ready for your microwaved meat and potatoes.
However, you should maybe rethink the free meal - it may be contributing to your jet lag when you get off the flight.
Melissa Biggs Bradley, the founder of the luxury travel firm Indagare, toldBloomberg:
Ten years ago, it was [a cabin crew member] on Singapore Airlines on what was, at the time, the longest flight in the world (17 hours from Singapore to New York).
She told me that her tried-and-true trick was not eating in-flight. Basically, at superhigh altitude, your digestive system shuts down completely.
Someone said to me it’s like being under anesthesia.
So when you get off the plane, everything restarts and [your digestive system] has so much more work to do and so it makes you more tired.
It's sort of true that we only eat on a flight because we're bored.
Can you earnestly say you've been hungry on a flight? We're willing to bet most times your stomach was in a knot and you simply didn't want to turn it down.
Some have dismissed this claim:
Insider spoke to nutritionists who contradicted Ms Biggs Bradley's statements.
Carolyn Pallister, Dietician and Public Health Manager at Slimming World, said:
Suggestions that your digestive system shuts down during a flight has no scientific foundation. By restricting yourself and not eating for long periods of time on a long flight you are likely to feel weak, shaky and could even suffer from headaches and low mood.
It is true however that a pressurised cabin can be dehydrating, so enduring that you drink plenty of fluids and avoid too much alcohol.
To satisfy appetite, eat foods including some starchy carbohydrate like potatoes, whole wheat bread or high fibre crackers or cereals, lean meat or fish and plenty of salad, vegetables and fruit while flying will help you to arrive at your destination feeling as fresh and alert and full of energy as possible.
In addition, if you're using the toilet on a flight, the chances are your digestive system is working. There's your evidence.
In short, the best advice is probably to stay hydrated and eat when you're hungry. It's true airline food is salted to preserve it - so maybe pack some fruit in your hand luggage.