It's a stewardess secret, but you should never eat on planes

A travel expert has advocated against eating during flights to prevent against digestive issues and fatigue.

As Melissa Biggs Bradley, a frequent traveler and founder of a luxury travel club called Indagare, told Bloomberg, "I eat nothing on flights...it's a stewardess secret."

She explained, "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."

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She went on to talk about the high levels of sodium and preservatives plane food tends to have.

Peter Jones, a travel catering expert based in the U.K, told the Daily Mail that each meal contains about 1,500 calories, and admits that "Airlines are not hugely concerned about nutrition..."

Part of the challenge airlines face is that foods taste more bland at high altitudes due to the effect cabin humidity and air pressure can have on the nasal passages and taste buds, notes The Telegraph.

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But budgetary pressures and on-board preparation constraints also influence the quality of food provided.

For those who still want or need to eat on a plane (of course, there are unavoidable instances, like super long flights or plain-old hunger), however, USA Today recommends that travelers protein-rich items like nuts or cheese which can survive packing and stave off hunger for longer.

Meanwhile, foods to avoid include gas-causing ingredients like beans or broccoli, and greasy dishes which may smell.

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As for Biggs Bradley, she says her approach is to "have something to eat a couple hours before getting on the plane, but otherwise it's nothing but lots and lots of water."