<<Disclaimer: Verify this information before applying it to your situation.>>
 
I always take a supply of my own food and bottled water with me when I travel
on airlines.  It helps to deal with airline surprises and ensure that I do
get something to eat if mistakes are made.  (Actually, I take a tiny supply
of food with me whenever I'm to be away from home for 5 hours or more, and at
least a half-liter of water at all times.)  I have to because not only must I
eat GF, but I also have to eat meat-milk-egg-free because of problems
digesting animal proteins.  And I have to eat on time, when I'm hungry, and
not when it's convenient for the airlines to feed.  And the airlines (and
other food providers) have trouble coming up with meals that are calorie
sufficient, nutrient sufficient, GF and meat-milk-egg-free that they can
serve me when I get hungry.  American processed foods--things like salad
dressings, snacks, etc.--are often filled with chemicals I choose not to eat.
 The flight attendants are busy--they have so much to deal with.  So I take
charge of my own food.
 
Also aside from carbonated mineral water, the airlines use tap water for
people who don't want to drink booze, coffee, juice, or carbonated sodas.
 And as the alerts from Washington DC and other places over cryptosporidium
(sp?) indicate, no one with any immune-related condition should drink tap
water that hasn't been boiled and filtered (that includes using ice made from
tap water...).  Who knows where the water comes from?  I read in a book on
airline safety that carbonated beverages expand  in the gut in pressurized
cabins (moreso than takes place on land) and cause all sorts of discomforts,
and found that after I stopped drinking colas on planes, my airsickness
incidents went *way* down.
 
This also helps in dealing with the situation in American airports, where
there is a shortage (complete absence, in many cases) of safe non-junk food.
 If you have a three hour wait to change planes, and you can't eat hotdogs,
cheesburgers, fries, colas, milkshakes, chocolate bars, salted peanuts, and
pizzas, it helps to have your own food and beverages.
 
 
Here's what I take with me on airlines:
 
1 1/2 liters of bottled water; more on international flights (I drink
   distilled water)
1 or 2 bottles of Snapple or homemade lemonade
2 to 4 pieces of fruit (depends on length of flight)
a salad with my favorite ingredients (and lots of cherry tomatoes!  I leave
   the small cucumber uncut)
GF condiments that would accompany my food:  tamari sauce, salsa, dips, salad
   dressing
A few selections of GF desserts/nibbles/snacks (cookies, rice crackers,
   potato chips, trail mix, etc.)
A small amount (8 oz volume or less) of a prepared main dish that travels
   safely
bamboo chopsticks, fork, spoon, knife
napkin or large travel tissues
A couple of plastic grocery bags, for disposal
 
These items fit into a small area of my large travel purse, next to the
magazines, newspaper, books, and other stuff I like to take for on-board use.
I it store under the seat in front of me.  I pack these foods in plastic
containers that I've recycled from other foods and water,  in ZipLoc bags, in
the tiny jam/marmalade jars I've saved from hotel trips, or in small spice
containers.  (I realize that some people may have objections to plastics,
though...).  If you take a thermos, you may or may not be allowed to take it
on board, because the mirror-lined glass will show up on the x-ray as
something suspicious, and the security staff may ask you to empty the thermos
to check the contents (this happened to me).  Take one of the wide-mouthed
plastic thermos bottles instead.  I ask the flight attendant for an empty
drinking container.  When they start serving food, I let them give me a tray
with airline food, and I replace suspicious items on their tray with my own
food.
 
On international flights, I leave any uneaten produce on the plane, since it
can't be taken into the destination country.  I also leave the rubbish on the
planes, since  many airports have removed trash cans from inside airline
terminals to prevent opportunistic terrorism.
 
I hope this helps...:-)
 
Sue