I couldn't tell you what the calorie count is, but I make mine with Whole wheat flour, and is made to the 1855 regulations. I cannot give you the recipe at hand, but I will tell you this. Once it sits, its as hard as concrete. I guess that's why the soldiers complained about it.Put either in a cup of Coffee, or in Bacon Grease to make it pliable. I suppose it would keep the soldier through the day, maybe with some sliced meat of some sort. I make mine just as a Haversack stuffer to show the public at my living histories. Its a big hit.