Food/eating i have learned is very personal

My husband enjoys oatmeal and can last hours on a good bowl. I eat the same bowl, and i'm hungry an hour later.

I need protein for myself, in fact a hearty breakfast of one egg, one piece of veggie sausage, toast, and 1/2 cup of fruit lasts me for a couple of hours with some snacking during the ride if longer than 2 hours.

Hubby would barf with that in his belly before a ride.

So you need to decide what works for you, which might mean experimenting a bit.