I have ridden thousands of miles on tours and with daily distance of more than 100 miles and the only snack I take is one or two small boxes of raisins. I am allergic to raw bananas or I would take one of them in the pocket of my jersey. The fructose in raisins is readily available to the body. Adding in nuts provides fat but they take longer to digest and process than the raisins.
My breakfast is a carb one of pancakes which provides most of the fuel for the day. One can also carbo load with pasta and such the night before but I have not felt the need to do this for normal riding.
Carbs in a snack bar or gel packet are not going to provide lasting energy for the body. They also result in getting hungry sooner.