I take MRE's on canoe trips as a "treat".freeze dry gets old after a few days.i would suggest just taking the meat packs without all the sauce in them.beef stew with all the vegetables is a filling meal but heavy.after a trip with those type packs I got the pork rib,chicken patty,and beef patty.adding instant rice or some sort of pasta on the side makes a real filling meal.
the Spam singles need to be fried otherwise they are just salty blobs if cooked in any sort of stew type meal.a single cooked up in a pot of Knorr rice side,teriyaki,was one of the most nasty meals I had on the canoe trail
the meat patty's can be eaten cold or the pack heated in any water you might use for something else.
half a Cliff bar was enough to keep me going between lunch and dinner but expect a hard chew.i can't say enough good things about some sort of hard chocolate with fruit and nuts in it.
I cut out hard sausage because it's salty and leaves a taste in you mouth for a long time.
if you want real hard core survival food make up ground toasted corn and take it with water.it expands in your stomach and has all the nutrition you need.i tried that when I was much younger at home to see if it worked,it does but it's not a real meal just something to keep you alive.