Proper fueling while running an ultra is somewhat of a religious topic. There are many things that work and nothing truly is sacred, to be successful. Some ultrarunners are vegans, and most eat meat. Some believe drinking soda is harmful, and most drink it freely during races. Some think you should drink constantly, others when you feel thirsty. Some think beer is heavenly liquid, others consider it to be unhealthy and dangerous. If you get a chance, volunteer at an aid station during a 100-miler and watch what people eat and drink from the aid station or from their drop bags. Fueling strategy can be all over the map. Figure out what works for you.
To be successful in ultrarunning you must keep in careful balance:
1. Calories
2. Fluids
3. Electrolytes