Eat what your body feels like eating, don't eat b/c you're "supposed" to. Your body knows most often what it needs. The night before my fastest century, I had a normal sized dinner that happened to be pasta (and REALLY good pasta), and then ate whatever looked good at the rest stops. Granted, I also had an electrolyte drink and some shot blocks to keep me going between stops, but I know that if I hadn't just gone with the flow when I saw food (banana? Yum! Nuts? Yum!) I wouldn't have done as well.

BUT. Don't overeat either. Remember that you have to keep going and the last thing you want is a lump in your stomach. Be reasonable, but trust your gut. Almost literally.

Thanks for this, it makes good sense. The whole "effort management" thing is not natural for me yet, so I tend to start long rides at a higher intensity than I should.