By Venus Gentile 7% of the carbohydrates and 12% of the proteins that we consume are used up in the digestion/assimilation process. Most people don’t realize that it takes a certain amount of energy to digest and assimilate the foods we eat and the harder our body must work to digest these foods, the less nutritional availability there is for supplying energy and rebuilding cells. 3,500 calories when consumed and unused (not burned for fuel) will put on 1 pound of body fat. J