Practical Method of Diet Calculation.—The 100-Calorie portions can be used in a very practical way for computing the fuel value of one's daily diet. In Lesson CXVI the weights of 100-Calorie portions of flour, butter, sugar, etc., were determined, then these portions were weighed and measured. In much the same way, tables have been prepared containing the weight and measure of 100-Calorie portions. If such a table is read and the quantity of the various ordinary foods that will produce 100 Calories of heat is kept in mind, the computation of the meal becomes very simple.
If a person knows his energy requirement, he can select such quantities of food for the day as will conform with the ideal standard. The quantity of food to be used at each meal is a matter of personal choice. The important point is to have the food of the entire day conform to the standard. However, in computing the energy value of the foods of each meal, some find it convenient to divide the day's ration. The following is a convenient division: One third for breakfast, one fourth for luncheon, and five twelfths for dinner.
But the division may vary with individual needs. Ascertaining one's energy requirement and deciding upon a certain division for the three meals, one can very easily select such quantities of foods for each meal as will conform with the ideal standard. If the energy requirement of a girl of fourteen years is 2200 Calories, her breakfast may yield approximately 750 Calories, her luncheon 550 Calories, and her dinner 900 Calories. A luncheon consisting of an omelet made with one egg (50), one medium slice of homemade bread (100), orange marmalade (100), butter for bread (100), large banana (100), and a small glass of milk (100) would yield sufficient nourishment according to the requirement above.
If it is desired to compute the Calories produced by the protein of a meal, data can be obtained from the table also (see Calories Derived from Protein).
The calculation of the protein content of the luncheon above is:
Number of Calories derived from protein of egg 18.2
Number of Calories derived from protein of bread 13.8
Number of Calories derived from protein of marmalade 0.7
Number of Calories derived from protein of butter 0.5
Number of Calories derived from protein of banana 5.3
Number of Calories derived from protein of milk 19.1
——
Number of Calories derived from protein of entire meal 57.6
If one tenth of the total energy requirement is taken as the desired protein requirement, the above luncheon approaches the ideal.
The Form C given below will be found convenient to use in calculating the fuel value of menus from 100-Calorie portions.
QUESTIONS
Calculate your own breakfast, luncheon, and dinner energy requirement, and those of at least two members of your family.