I consider your lunch rather small. There is NO FIBER, i.e. no fruits or vegetables added to your lunch. Fiber plays a role in satiety. If you are hungry, pack some fruits/veggies--there are TONS of safe options. Also, your carbohydrate choices are rather high glycemic which could play a role in your hunger. Perhaps substitute those "light chips" with something that has more staying power in terms of satiety as well as nutrient merit. Consider making your lunches more interesting and up the quality of nutrients.
One question: how long does it take you to consume your lunch? It takes about 20 minutes of munching to register a sense of satiety.