how are calories added into MREs?

[Eddo36]

How does a relatively small amount of food have so much calories? Something high-calorie added to the ingredients like sugar?

[Militaryration_guy]

How does a relatively small amount of food have so much calories? Something high-calorie added to the ingredients like sugar?

I'm not a food scientist but I think that it's the carbohydrates that make MREs so high in calories.

[Smitty]

By weight, you have roughly 4 calories per gram of carbs and protein, and 9 grams in fat. Most western rations are pretty low in fat so it’s really not as high as it could be. All they gotta do is keep the carbs high through sugar and flour, add a bit of fat and protein and you have a fairly high carb meal. If it was a big old chunk of fat, the ration would be smaller and still calorie dense..albeit not incredibly shelf stable.

[Tedster]

I actually wouldn't call them particularly high in food value or calories. About 1200 calories per meal. And much of the calorie count is derived from refined carbohydrate. Sugar. 3600 calories per day is considered sufficient for an adult male with a "moderate" strenuous work load outdoors, or somesuch.

Sugar isn't all bad, it is immediately absorbed and ready almost instantly for quick energy. This is one reason though why it is so bad for inactive, sedentary people, excess glucose is stored in the liver, muscles, and bloodstream. Any calories over and above normal requirements are converted to fat (adipose tissue). Sugar or refined carbs especially is like rocket fuel, except, people aren't aiming for the stars, they sit on the couch and watch TV (yet another poison, basically).