Originally Posted by ivan_yulaev

Hmm, I can't eat heavy foods in the morning. I usually show down like 6 small donuts or cookies or something. I find that simple carbs are easier to digest.

That aside, if you're doing a century, you will bonk at ~70 miles in without nutrition. Glycogen supply is about 3000 calories, this should give you 50-80 miles (or so), but I'd be surprised if anyone could do 100 without any sort of calorie intake, without bonking.