I usually wake up starving since I don't eat full dinners, so I eat a regular breakfast before leaving, but I give myself at least 30 minutes after eating before hopping on the bike. Nothing special: black tea, multi-grain toasts with cream cheese, yogurt, banana, sometimes boiled or scrambled eggs. I sometimes bring lunch with me, sometimes eat out, depends on the situation, mood, etc. One thing I noticed is that I eat less on a normal day since I started commuting by bike.