This is the one thing you shouldn't do before your flight if you want an upgrade

And no, it has nothing to do with what you're wearing

Want to know how to get upgraded on a flight?

The typical advice for getting bumped up to business generally includes things like 'dress up', 'ask politely' or even 'pretend it's your honeymoon' (who on earth would do such a thing? *cough* me twice *cough*)

http://giphy.com/gifs/bridesmaids-xSoDPvQVC785y

But there's one thing you might not have considered in your eternal quest to turn left: food.

Nik Loukas - who has worked in the flight industry for ten years - told Business Insider that making a specialist food order ahead of your flight will rule you out for an upgrade completely.

'If there’s a special meal request in your booking, the airline won’t even look at you [for an upgrade]' he said. Purely because - stating the obvious here - it's a lot harder to make last-minute provisions if the customer follows a particular diet. 'If you've got a dietary requirement they might not be able to cater for you if they upgrade you' he adds.

If you're flying BA, the range of specialist meals you can order before take-off includes lacto-ovo-vegetarian (no meat, fish or seafood), vegan, vegetarian, low calorie, low salt and low fat, as well as Kosher, Muslim and Hindu meals. All of these have to be requested at least 48-hours before departure, and according to Loukas doing so will automatically bar you from a seat beyond the blue curtain.

If you do have a specialist diet and want an upgrade, the only current solution is to order a standard meal and bring your own grub. If you're in it for the leg room and booze that could be worth it - though it's a bit of a risk given the likelihood of being upgraded is still pretty slim, particularly now it's more common for airlines to offer fliers the option of paying up last-minute for a better seat. As this writer discovered when she flew back from LA recently...

Me: 'Any chance of an upgrade? *winning smile*

Lady on desk: 'Certainly ma'am' *tapping on keyboard*

Me: 'Great!'

Lady on desk: 'We can do that today for an additional six hundred dollars'