Since your flight leaves in the morning, I would say don't eat dinner (or not much, at least) the night before. Definitely skip breakfast. Also, don't eat all of anything they bring you.

I only fly BF to South America, and when I do I'm so stuffed by the time dessert comes around I can't even imagine eating another bite.

Others likely have several recommendations, but since I love to eat and am not big enough to hold everything they bring me, I would just say to sit back, don't eat all of the first items they bring you (unless you're accustomed to eating large sums of food in one sitting), and enjoy!