Those of us who have marathon reading sessions know that you have to be prepared. Plenty of snacks and hydration within reach are required. Everyone has their preferences regarding what those are and certain rules that they may apply (such as nothing greasy so that you don’t mess up pages).
I will typically make myself a plate with an assortment of things such as some kind of fruit (apples, grapes, strawberries), cheese, crackers and more. Variety of items means that I’m not going to be searching for more snacks in the middle of my reading. I also make sure that I have water and some other kind of beverage available that contains caffeine such as Diet Coke, a chai latte or coffee.
For me the main point of getting set up with snacks and drinks is to ensure that I have everything I need for a long reading session. If you are deep into a book you are not going to want to stop and go foraging. Not everyone is going to have the same habits, but that’s what works for me.