Take a book to read. I do it sometimes and it helps pass the time. Also, you could take an apple to cover up the scent after you eat something. I would suggest packing beef jerky, or crackers, or gum, or anything that will fill your gut. Sitting it out til after lunch ain't an easy thing. And pack a lot of water. Water takes the edge off of hunger...and being thirsty is a major demoralizer.

Hope that helps. Good luck.