<<Disclaimer: Verify this information before applying it to your situation.>>

Thanks to all who responded to my post on whether you can take GF
foods to Mexico.  The universal answer was that you can.  I received
suggestions on what to take, and what is available there as well.
Below are some selections:

Yes, you are permitted to take food items out of the country--you're
just not allowed to bring any food items back into the country!

While traveling in Mexico I never take food down there. It is alright
to take packaged food such as crackers or canned food.  Fresh foods
are a no-no. If you go to authentic restaurants (not chain -
especially American like Planet Hollywood or hotel) you are usually
very, very safe with Mexican food like Enchiladas, Tostados, etc.
and sometimes if the recipe calls for wheat (trigo) flour I ask them
to substitue the corn(maize) tortilla.

I think I checked a web site or called the State Dept. to get a list
of foods you can't take in.   Most pre- packaged foods are fine.   I
think mainly they were not wanting you to bring in fresh veggies,
meats, etc. Also, it was easy to shop in the Mexican (larger) grocery
stores. At restaurants, they had plenty of corn tortillas and fish,
chicken, etc, and veggies that are ok for us

When I was down in Mexico this last November I was quite surprised
that in a lot of the nicer resturants they made their flour tortillas
out of corn flour separate from the wheat flour ones and used a lot
of cornstarch for their foods instead of wheat. Corn is a staple of
Mexico. That is what a resturant owner told me. He was aware of this
type of a diet. He said just ask if they have whatever in corn
instead of wheat.

I took GF cookies, pretzels and some bread with me.  I was never
asked if I was carrying food products on entering Mexico. I went to
Cancun and declared the food I brought with me.  They seemed to be
most concerned about having it closed and packaged