Skimmed milk contains very little fat. If milk is drunk by the adult, as a means of storing up more fat within the body, the cream, if assimilated, should be stirred into it.
The Fat of Meat. This should be thoroughly cooked. All meats in the process of baking or frying should be covered, in order to retain the moisture. The fat in well-roasted beef is nutritious, but to make fat easily digestible it should be well masticated so as to break up the tissue fibers which surround it.
While fried foods are difficult of digestion (see page [192]) because the surface albumin is coagulated and the hot fat forms a coating around it, making it difficult for the digestive juices to reach the tissue, the fat of bacon is more easily dissolved because of the delicacy of the fibers surrounding the fat cells. If thinly sliced and fully immersed in its own grease in the process of frying, bacon is an easily digested fat. The process of smoking the bacon renders it easier of digestion.
Cooked bone-marrow is an easily digested form of fat which is usually relished by those to whom any other fat is repulsive. It is useful in some forms of anemia, as it contains considerable iron.
Eels, salmon, and mackerel contain much fat.
The Eskimos extensively use both whale and seal oil as a food.
The yolks of eggs are also rich in fat.
Cod-Liver Oil, pressed from the liver of the codfish, is easily absorbed and assimilated by some. The odor is not pleasant and a little lemon juice, salt, baking soda, or any flavoring substance may be added to make it palatable. The pure oil taken in this way is, perhaps, preferable to the prepared emulsions.
Olive Oil is derived from ripe olives. It is often used when cod-liver oil is not well borne. Many take olive oil for the purpose of rounding out the figure with fat. If the system will assimilate fat, taken in quantities, the fat may be stored; but, as a rule, one is underweight because of a failure to assimilate the regular diet and overloading the digestive organs with fat will not cause a better assimilation. If the lack of flesh is due to sluggish assimilation exercise should always accompany a diet for the building of flesh.
Olive oil, in moderation, is a good food when much heat and energy are required, but if one’s occupation is sedentary, much fat is not necessary.