Most of my 50 Km rides start between 07:00 and 09:00 and I don't like to eat much before the off either. Usually a couple of jammy toasts and a coffee 45 minutes before, and then a power bar or banana as in ride fuel. 500ml of water sipped as I go along. The power bar/banana is never eaten whole, but in maybe 2 or 3 separate mini breaks through the ride. I never feel nauseous unless I'm really gunning it although never been physically ill.
I don't actually eat a great deal more on a 100km, an extra gel or bar/sweets, and don't eat any more pre-ride. Always carry cash in case I need to buy a sugary/energy drink if I unexpectedly start to flag severely.
For reference, I average about 23 km/h over 50km.