This section is from the book "Economical Cookery", by Marion Harris Neil. Also available from Amazon: Economical Cookery (1918).
"Cut and come again."
Twice-cooked meat is not injurious unless it is heated in such a fashion as to render it hard and leathery, in which case undue strain is thrown on the digestive organs. This is especially unfortunate when it occurs with individuals who are physically or mentally fatigued. Cold meat reheated is less nourishing, because no matter how careful the cooking process, a certain amount, however small, of the nutritive juices escapes during the first cooking, though retained and served as gravy. When the meat is reheated, this gravy having been used, and the juices which have escaped from the cut surfaces into the dish having dried, the meat contains not only less flavor, but also less nourishment. The cook, if she be wise, adds, to recompense these losses, various piquant flavorings, extra sauces, and so forth, producing finally a very savory and easily digested concoction, but still one actually less nourishing than a freshly cooked steak or cut from a joint, supposing them to have been correctly prepared in the widest sense of the term. In cases where meat has in the first instance been stewed to rags or badly over-roasted it has but a low food value, even when first served. It is necessary to bear in mind that meat should never be actually twice cooked; it requires not cooking, but, if possible, merely reheating. It is the faulty method of utilizing cold meat that has given it a bad name.