As mentioned, best to ask for a 2nd main when they're done serving passengers. Crew will not let your have a main mid-way through the flight when you ask for one. There are cup noodles, but it's the small sized ones, and not the standard sized ones sold at the supermarket. There is also a snack bar (biscuits, peanuts) available throughout the flight as well as fruit (ie. whole apple) and you can try to fill yourself up on that. Otherwise, you're out of luck, and will have to bring your own food.