Not too sure if you get them where you are, but here in Australia we can get foil packets of salmon or tuna (with or without added flavours like smoke, tomato & basil and the like), and those foil packets are heaps better than cans, pack easier and weigh less. We used them on on our Australia tour and found them great. Another idea is to do some meals and dehydrate them. You can get a good book for that called "the backpack gourmet". make em, dry em, pack em and eat em. you can carry lots too because they weigh nothing. you will however need water to cook them in so a long desert trip is probably not the one to take them on.
Enjoy.