I use nuts, dried fruit, and cereal bars as snacks during the day (I snack periodically throughout the hiking day instead of eating lunch). I would never, ever use them as a sole diet even for a short trip, though. I also vary the snacks from trip to trip.

Hiking and backpacking are supposed to be fun, not self-sacrifice! Unless your idea of fun at home is a sole diet of one thing or another, please don't ruin your recreation by forcing yourself to eat a monotonous diet!

Of course if you get satisfaction out of feeding a martyr complex. . .