Mine depend on the day and the time …
If I’m reading in bed on a Saturday morning, I like a nice cup of coffee (or two).
If I’m reading in the afternoon or evening, I tend to drink green tea or a herbal tea (or perhaps decaf Earl Grey). Sometimes I’ll have hot chocolate.
I shouldn’t snack while I’m reading because it tends to be empty calories (i.e. no nutritional benefit). If I do snack, it’s likely to be cheese and crackers, or chocolate.