I try to bring my lunch to work every day, for health and financial reasons. Here's my typical workday lunch:
I always have breakfast on my first coffee break - I have a protein shake made with 1 cup of almond milk, 1 scoop of Vega Whole Food Health Optimizer and 1 cup of water. Sometimes I add a bit of coconut milk for some variety.
At lunch time I have 1 cup each of organic apple sauce, baby carrots and grape tomatoes, and 1.5 cups of home made hummus with whole grain crackers or thin rice cakes. I also keep a package of granola bars in my locker (right now it's Kashi Dark Chocolate Coconut Bars) for days when I just need a bit more to keep me going.
On my afternoon coffee break I'll have an apple or some dried fruit & nuts.
I also drink at least a litre and a half of water during my workday, which helps me stay awake and stay focused, and it forces me to get up and take bathroom breaks!