I've got several ideas, but it depends upon where you are going to be doing your shopping- Of course I like to make a lot of my own food, but that's not feasible for everyone. If you are in the States there are several products you can buy or make easily that are a pretty good ratio of weight to nutrients. If not, hopefully you can find or make their equivalents:
-Tankabars! Buffalo Cranberry bars- very Yummy.
-Beef Jerky (either dehydrate your own or store bought)- Paleobrands has one here
-Pemmican- either make your own or buy it
-Canned Sardines (although the can is extra weight that you would have to pack out).
-Canned or bagged Salmon, Tuna, Chicken, etc- Stores now carry bagged meats that should contribute less weight and trash to carry out.
FATS - I run well off fat, even at pretty high altitudes, but you may need to experiment to see if you will need a higher carb mix
-Justin's nut butter packs- almond, Hazelnut,some have a small amount of added honey or maple sugar etc (if you don't have nut issues)
-Mrs Mays nut crunches
-Coconut butter- repackaged of course...
-Homemade Coconut oil/nut crunches (NOTE: depending on the temp of where you are hiking these may melt).
-Coconut oil for any cooking, or potentially ghee if your temperatures will be low-ish even during the day.
-Spicy sweet Walnuts: (for 1/4 lb)- warm up several (I use 4) tablespoons of honey at low heat in a frying pan or pot until liquid and slightly bubbling, mix in ground black pepper and sea salt to taste (I use about 4 -5 tsp ea). You can also add cayenne pepper or anything else hot if you like the kick. Turn off the heat and add the walnuts in last. Mix the walnuts around until you have even coverage of the honey/spice mixture on them. You do not want to cook them, you are just trying to coat them.
If you're adventurous you can try adding different spice mixtures to different nuts for variety... Also, you can add in some blackstrap molasses if you want some more minerals.
-Dried seaweed sheets or seaweed snacks- I'm a freak and like plain Nori Sheets
-Dehydrated/freeze dried beet chips, apple slices
Paleo Friendly fruit/nut bars:
-Extra Dark Chocolate
Also- as long as you are not hiking in high temp areas like the desert (which you are not!)a nice trick for the first night is to freeze up a steak or another luscious hunk of meat the night before your trip. Make sure to seal it well in some plastic baggies and stow it to the center of your food storage area to insulate it. If you will be using a bear can, pack it to the center. It will slowly thaw and by the end of the day you have a thawed steak just waiting for you. I've done this multiple times and its worth the extra weight. Especially on the first night of a long trip it's nice to have that last little luxury of a hunk of REAL protein.
Of course if you're a real gram counter, then just stick with the dehydrated foods- they do really help on the steep grades.
If cutting weight really matters to you, don't forget to repackage as much as you can. 1 ziplock baggie with 6 Tankabars in it weighs way less (relatively) than the packaging for 6 tankabars....
Also, if you are truly interested in cutting your weight, here's a link to my part of a gear list for a 220 mile hike of the JMT that we did in 09'. There are some great lightweight products in there like our gossamer gear tent and my 4.7 oz down jacket from Montbell.