I have found that the special meals can be a good deal. I
usually get the low cholesterol, or vegetarian meals because
they usually have plenty of fruit and fresh veggies.
Occassionally this hasn't worked out, and I got a much worse
meal than the regular, but usually it is better. One added
advantage is that you get special service, the waiters
(excuse me, flight attendants) bring all the special meals
out before they serve the regular meals, so you have the
added pleasure of eating first while everyone around you is
still waiting. Childish, yes, but a small pleasure all the same.

I always carry a good supply of snacks too.