This has been a challenge for me.
Without owning a food dehydrator, I was limited the last time I went out for 3 day trip on the AT.
If I remember correctly, I did my homemade cereal for breakfasts. Theres no recipe really, its just mainly a combo of sliced almonds and shredded coconut, with some honey and pumpkin pie spice, baked on a cookie sheet until crispy / crunchy. I just ate it dry while walking. I don't miss cooking and eating mushy instant oatmeal one bit! I was able to keep up with my hiking partners eating their pop tarts while hiking, and I stayed full longer.
Lunch was foil packet tuna (in olive oil, not water!), with some relish and mustard packets for impromptu tuna salad. If it weren't for cost I would have just done jerky and some dried kale or seaweed.
Dinner was some eye of round beef jerky I dehydrated in the oven (kind of a pain)and some baby spinach, with some bullion for a soup.
For snacks between meals, I ate a lot of almonds, macadamias, dried fruit, and Larabars. I found myself looking forward to the chewy sweet Larabar and kinda disgusted by almonds after 2 days out. Dark chocolate was a precious commodity I wish I brought more of, I definitely reccomend it for the fat you need to stay fueled, and that is hard to get from other sources.
After a year of being paleo / primal, I also find that rice in moderation is not a huge deal to me and I sometiems have it, even while abstaining from other grains. If I had to pack up today for a trip, I would do some instant rice or instant potatoes to help fill out dinner. I also want to buy a dehydrater to bring out more veggies / homemade soup mixes.