I really look at the food I take on a trip as equally important as my shelter, or water. Take advantage of what people have learned about nutrition, and use it your advantage. You don't want to learn the hard way when you run out of food, are still hungry, and a day or two away from your ride home. That being said, I think everyone brings the necessary indulgences on a trip. I don't know what I'd do on a trail in the middle of nothing when my sweet tooth kicks in and I didn't take along some junk food.
On the topic of MRE's, I've always had great experiences with them. While I was never forced to eat them for a period of time, they come in handy during bad weather. Every time I've gone out, it rains cats and dogs, and I've always had 2 MRE's as a backup if I wasn't able to cook. To me they are one of those things you take not because of a few scenarios you can think of, but all the other stuff that could happen that you can't think of. Besides, you can't get more romantic than in a tent, with a candle lantern-lit dinner in the middle of a thunderstorm. She almost thought I planned it, except I'm not in charge of the weather <img src="/forums/images/graemlins/cool.gif" alt="" />