For years my breakfast was coffee followed by 1 banana with peanut butter and 5-6 egg whites. Then I would put in a 3-5 mile run 4-5 days per week on that breakfast.
Now since I start work anywhere between 0445 and 0500, I'm not hungry at all when I get up and drink coffee until I get to work. Usually around 0530-0600 I start to get hungry and eat some yogurt, drink a protein shake (w/ almond or coconut milk) or have a banana w/ peanut butter.
For snacks I have carrots, a Nutri-Grain bar, Belvitta breakfast biscuits, protein bar or a banana w/ peanut if I didn't eat one earlier.
For lunch I'll have grilled chicken with a huge handful of spinach, some carrots, broccoli and add some fat-free dressing. I grill a bunch of chicken on Sunday to last 3 days so I can quickly gather a good lunch for work. The chicken, carrots and broccoli are cheap. The grill was not. :)
The key is to not eat carbs that quickly raise your blood sugar. You need carbs but choose them wisely. Whole grain carbs accomplish this and if you eat plenty of food with fiber (whole grain carbs are not refined thus they keep their fiber and other nutrients that are otherwise milled out), you'll feel "fuller" longer after you eat and besides, fiber will change your life.
For example, right now, 45% of my calories come from carbs and I'll never, ever go below 40%. That's 900 calories from carbs per day for me. If I were to eat mostly processed and enriched carbs, I'd be freaking hungry all the time as my blood sugar would spike instead of gradually rise. Of course I eat enough crap that I shouldn't but I sure can tell a difference after I eat it.