If you preorder a special airline meal (e.g. vegan) just to try it, does this inconvenience the caterers and staff?

Vegan is not a ‘special’ meal

There’s absolutely nothing special in a vegan meal. A vegan meal consists of vegetables, which are a basis for every healthy meal. It just doesn’t have meat as an addition. Think of a non-vegan meal as special, because an extra component is added.

Everything about you is an inconvenience to the staff

and they are being paid for dealing with that inconvenience. So don’t feel bad about pre-ordering a special meal or using the toilet during your flight (though Ryanair might charge you extra anyway).

Offers are driven by demand

If nobody would take the vegan option, it would disappear. If more people take it, they will prepare more vegan meals in advance. Maybe someday meat will be considered an extra need (and charged extra?)

It probably depends a lot on your airline and your departure airport.

Are you taking a major airline, from one of their hubs? They handle tons of special meal requests every day. One more or one less request won’t make a difference, as long as it’s been entered into their computer in time. With a small airline and a small airport, it could be a bigger issue.

Some airlines simplify things by preparing a reduced number of special meals. Each meal type may cover multiple categories of dietary restrictions at once. For example, the vegan meal and the vegetarian meal might both be identical: both meals might actually be made up of the exact same vegan foods.

(Adapted from a comment by jcaron.)

It is not bad to order a special meals for each of the reasons mentioned in the other answers (and comments) and use it, as long as you do claim what you ordered, (eat it or not, but do not claim an other meal.)

Sometimes they run out of certain special meals, because not enough were send to the plane for this flight, there is nothing you can do about that (other than if you hear it and you do not really need a special meal, you offer it to the flight attendant.)
But sometimes they run out because people claimed to have ordered a special meal but did not and people who really need the special meal and ordered it have to go without, which is bad. So unless you have ordered a special meal do not claim one.

The price difference between one airline meal and an other will not be huge and sometimes the special meals are cheaper which offsets the ones which are more expensive. That should not be enough of a reason not to order a special meal, airlines can raise ticket costs if it gets out of hand, or downgrade the meals, special or all.

While I can’t really see ordering a vegan meal "for fun" you will not be consuming a limited resource or depriving someone else of what they really need. A meal will be available for you and for everyone else who has ordered one.

Reasons I have heard for ordering a special meal include:

• the Indian vegetarian meals are usually much spicier than any of the regular choices
• you get yours first and you know what it’s going to be. With a seat at the very back you may find there is no longer any choice by the time the cart of general meals reaches you.
• they believe halal or kosher meat is higher quality (of course, some airlines achieve halal by not giving you any meat)
• they have a strange allergy (eg all citrus) and staff often don’t know what is in the regular meals. For special meals you get full ingredient lists
• the parts of a special meal are often individually wrapped and made to be ok at room temperature, making them easier to slip into your bag for later

All of these are perfectly fine. You don’t need a "good enough" reason and there is no screening test or certification to prove you’re entitled to a special meal.

The only downside is that the staff hand deliver the special meals one by one to each person who ordered them. You are thus causing about as much extra work for the crew as if you ever ding your call bell, even by accident. This is not overtly selfish of you.

The downside for you is that sometimes you get a banana and an apology from the crew. Many people have told me the volume of food in special meals can often be less than you would want.

I’m not sure if this really is a comment or not.

I would argue that, if the airline has given you the option of ordering a special meal, then you are free to do so.

Airlines generally outsource their meal preparation to caterers. These caterers produce meals in bulk, and not individually. The cost of meal production will be aggregated over multiple flights. There will be an expectation of a certain percentage of passengers on a flight eating each type of meal. These figures will drive what meals are offered on each flight with the airline.

You, as an individual, will not upset the production of special meals, or the airlines’ economics of meal supply. Even if every passenger on one flight ordered a special meal, the airline knows this ahead of time and can ramp up production before departure.

So, in my opinion, order what you like. The airline won’t question you on the validity of your meal choices.

Flipping your question around: Would you feel bad for not eating any non-special meal that was offered to you? After all, the airline went to great lengths to ensure that it had food available for you.