My stomach gets upset if I ride without eating anything at all as well. I only eat enough to settle my stomach, though. Like a 1/2 cup of fat-free cottage cheese, or about 100 calories of fresh fruit that is not too acidic. I prefer apples, melons, pears, and sweeter berries.
If I eat any more than that, I find that it is harder to get my legs or my heart rate going. I can make it happen anyway, but it takes a lot more mental effort to make myself do it.
I eat my real breakfast meal after the ride.