This is tough. Our first trip w/ DD (at 10 months) she didn't get near enough fruits and veggies. We vowed the next trip we would be better prepared.
What we did was we packed some canned fruits & applesauce that were the individual size. We ALMOST packed some of the smaller cans of veggies too, but decided against it when we tried to pick up our luggage and move it to the car.
DD is only 14 months, so we also packed some of the gerber graduates "tv dinners" that had plenty of veggies and sweet potatos.
When we did the grocery run for some adult beverages for the cooler we also picked up some bananas (you'll pay about $1.50 each at the food court). On the first trip we actually snuck a couple of bananas out of one of the buffets because DD needed them so badly.
When we ate at Jiko the second time they had a side of peas & carrots that we ordered for DD. It was easily 2 cups of veggies (that she loves) If we had had something to put it in, we probably would have taken the leftovers with us.
*Most* of the restaurants are pretty accomadating, and most of them now have healthier choices (Carrots (raw) instead of fries, Soup options, etc.)
Try getting the kids a cup of veggie soup at the counter service places (if they are little - like mine - just drain off the liquid and let them eat the veggies).
We had to be creative, but carrying those fruit cups was a life saver. It made for a great morning snack for her and a great break for us.