The meals are pre-planned, they are conveniently sealed and stored away for a later date. Granted, the lifespan of homemade MREs will not be comparable to the 10 year lifespan of government issued MRE's, but they have a few advantages of their own. For one, making your own MREs is less expensive and they have fewer preservatives, thus causing fewer intestinal back ups. And, of course the most important advantage is they taste better.

If you have certain food allergies or other dietary requirements, it would make more sense to make your own rather than gamble on an allergy flare up. With the homemade versions, you also have the benefit of having a re-usable bag, which can be used for carrying water, or being used to boil other foods.

As this site notes, MREs manufactured since 2005 are of equal quality and caloric value as military MREs.  They now average about 1,222 calories per meal. The typical MRE entrée has crackers (pilot bread), spread to put on the crackers, a side dish, dessert or snack, powdered beverage and an accessory pack with matches, gum, instant coffee, creamer, sugar, salt,  moist towelette and toilet paper. All of these contents are packed into a sealed heavy plastic bag.