Milk contains a considerable proportion of milk fat depending on the breed of the cow or animal; the percentage running as high as 20 with some animals, but generally being from 2 to 5 percent. In the case of those milks used as human food.
Butter contains 80 percent more fat, and since fat has twice more heating and energy value than sugars and starches, butter is a very valuable item in the diet: particularly In cold seasons and in cold climates is it appreciated.
Butterfat is more valuable than most fats because of its high content of some of another group of food substances which are essential in a diet, the vitamins.
From the energy and warmth giving point view, margarine is not greatly different from butter, but margarine is mostly made in varying proportions from premier jus (refined fat from meatworks) and coconut and other palm oils.
These substances are poor in the vitamins present in butter, although some of them are quite well colored, so that for the growing child needing a considerable quantity of the growth promoting and rickets preventing vitamins contained in butter, ordinary margarine is not a suitable substitute.
In some parts of the world margarine is churned with sour milk or minute amounts of diacetyl are added in order to give it a butter aroma and flavor; colored substances such as some of the deep colored palm oils or annatto may be added to imitate butter color, but these are forbidden by law.
Nuts, like peanuts, walnuts and pecans are all rich in fats and oils. In this connection fats and oils have a definite chemical and nutritional significance. But mineral “oils” such as medicinal paraffin, are quite different chemically and have no direct nutritional value.
Cod-liver oil is a true fat like milk fat, but is of importance in nutrition both on account of its energy value and vitamin contents. Eggs contain considerable quantities of fat in the yolks, and associated with this fat are vitamins.
What Foods Are High In Sugar And Starch?
These two classes of substances, starches and sugars, are similar and have a similar function in the body. Like fats they cannot be used of themselves for building the body proteins, but are sources of heat and energy.
All cereal foodstuffs, like the products of wheat, oats, barley, rye, and maize, are rich in starches, as are potatoes. Sugar cane, sugar beet, turnips, and carrots contain sugar. Sugar itself is commonly obtained from the first two, and a variety of sugar, glucose, may be made from maize and other starches.
Cereal foodstuffs containing starch are included in the diet because of their energy value and because they furnish other substances like mineral ash from which the hard parts of bone are made and the body tissues and fluids supplied with mineral elements; they also contain various vitamins.
The more hard work an individual is called upon to perform the greater the amount of cereal foodstuffs and potatoes which he can usefully consume; but he must have good protein foodstuffs for the repair of the complex human machine which wears, as does other less complicated machinery.