If you've got jersey pockets, your lunch is always under your control. On an 80-mile training ride, I'd stuff a bunch of Clif bars in my pockets and eat one/hour. Heck, put a sandwich and a banana in your pocket if that's what you want. If I'm riding hard a big calorie-laden lunch is usually the last thing I want.

If this is the case, you probably need to focus on your diet. In my experience, when I eat a carb-heavy diet (especially one with lots of simple carbs) I'm always hungry. When I eat more fats and proteins, and drink plenty of liquids, I'm almost never hungry. For me, the 40/30/30 ratio of Carbs/Fat/Protein seems to work pretty well.

Also, remember that your body adapts very quickly to any routine. I find it helpful to occasionally take a break from both diet and exercise, though not necessarily at the same time. Keep doing the same things over and over and eventually you'll stop seeing benefits. Eating a bit more or exercising a bit less for a week often helps me to push past a plateau. Changing my training routines also helps. Spin like a madman one week then mash a bigger gear the next week, or focus on sprints/speed for a while then slow down a bit and focus on endurance. Anything you can do to change things up should help.