A full day's ration should give you 4000 calories, well over the diet of most adults not running around in a battle zone. There's a lot of salt and fat in some meals - again, not a problem if you're active, but if you're using these as rations, look for supplements and go easy on the spreads and desserts. I've listed some of the nutritional information below. The meals include almost no vegetables. There are tomato sauces, and some small pieces of veggies, but you won't find broccoli or a salad.
Fruits are also at a minimum.
Most calories are from protein, starches and fats, generally in that order. Sauces may have extra dextrose for flavor as well as for energy. This makes them very useful for survival use, as a compact source of energy, but you will have to supplement your diet over the long run. There are tables published which give most of the nutritive values of each meal, broken out by package. Some outlet's catalogs will have tables.