Why we eat more on airplanes

There’s good reason why we can’t help but wolf down the calorific plane food we’d normally turn our noses up at, new research shows.

In his new book Gastrophysics: The New Science of Eating, British professor Charles Spence says that while meals served at altitude typically taste terrible, they’re often more desirable than meals at ground level.

The lower air pressure in the cabin, dry air and loud engine noise all dull our ability to taste and smell food and drink, he told The Telegraph. ‘‘Therefore, the food we consume needs 20 to 30 per cent more sugar and salt to make it taste like it would on the ground.’’

The boredom we experience on planes and the in-flight entertainment we engross ourselves in to relieve it make matters worse, he said.

‘‘With nothing else to do, food becomes an appealing distraction. And when it is being offered for free, it will be even harder to resist.’’

If we’re enjoying a film or TV show,

"With nothing else to do, food becomes an appealing distraction." British professor Charles Spence

we’re even more likely to shovel down copious quantities of unhealthy food, Spence said.

The average Briton consumes nearly twice the recommended daily intake of calories between their check-in at the airport and arriving at their destination.

A greasy meal and pint or two at the airport would certainly contribute but Spence, a lecturer at Oxford University, said plane food was the main culprit behind the sky-high calorie intake.

Some airlines have introduced healthier methods of making their meals more palatable, such as serving dishes that trigger our unami taste buds, like curries. However, most resorted to loading the food with lashings of salt and sugar.

Another tactic had been to bring in celebrity chefs to enliven menus, but Spence said this had been largely futile.

An Air New Zealand spokesperson said its culinary team planned the airline’s menus with the knowledge that our tastebuds change at 30,000ft.

‘‘For instance, we know our sweet and salty senses are significantly weakened at altitude so our onboard cuisine is seasoned accordingly.’’

The airline was unable to supply nutritional information on its inflight meals, such as the overall calorie count or amount of salt or sugar.

The spokesperson explained that meals were prepared by qualified chefs in more than 20 kitchens around the world using local, seasonal produce and specialty New Zealand ingredients.

New Zealand-based nutritionist and author Claire Turnbull said airlines often felt compelled to offer the kind of bland, unhealthy food they believed would appeal to the masses. They also had a fondness for serving foods such as ice-cream, which was easy to store.

‘‘Until everyone says we want it to change, it won’t change. And it may not because everyone loves ice-cream!’’