You can miss a meal. I usually sleep on long flights, and the flight attendants don't usually wake me for meals.
If you are worried that they might skip you because you are asleep, talk to the flight attendant and ask to be woken at meal times.
I HATE airline food, and generally plan ahead when flying. I usually take a snack of some kind with me to eat on the flight.
Bad as McDonald's is, I find the hamburgers taste better than airline food, and have made several flights with hamburgers stuck in my pockets/backpack to eat when I get hungry.
They tell you it is the altitude that makes it food taste bad during the flight, but if you take your own stuff with you, you will discover that it tastes the same as on the ground. Conclusion: Airline food SUCKS.
Then, they try to serve some kind of pseudo gourmet crap as though that's any better. Nope, they can't make it taste good, either.
Best airline food I ever had was on two flights. One was a military flight from Rhein-Main Air Base,Germany in a USAF C141 going to the US. Box lunch with a sandwich and chips. Tasted great.
The other flight was from Frankfurt to Budapest, Hungary. Ham and cheese sandwich on a pretzel roll with butter and lettuce. I asked for a second, but they were out because everybody else asked for seconds as well.
I think the airlines ought to just face the fact that food packed in plastic for hours, then reheated in a steam bath sucks. They could just serve something simple and tasty, and save themselves and the travelers a lot of hassle.
But then, what do I know. I'm just some guy who's had to eat the pathetic garbage more times than I really care to count.
Sorry for the rant. Just returned from a trip involving two international flights. Still unhappy about the crap food.