2. Necessary bulk or volume.
3. Desired physiological influence of the foods upon the digestive tract, whether constipating or laxative in character.
5. Effect upon health. It is recognized that there are foods wholesome and nutritious, that cannot be used by some persons, while with others the same foods can be consumed with impunity.
As explained in the chapter on Dietary Studies, the nutrients should be supplied from a number of foods rather than from a few, because it is believed the various nutrients, particularly the proteins, are not absolutely identical from all sources, or equal in nutritive value.
EXAMPLES
1. Calculate a ration for a man with little physical exercise.
2. Calculate a ration for a man at hard muscular labor, and give the approximate cost of the ration.
3. Calculate the amounts of food and the nutrient requirements for a family of seven for 10 days; five of the family to consume 0.8 as much as an adult. Calculate the cost of the food; then calculate on the same basis the probable cost of food for one year, adding 20 per cent for fluctuation in market price and additional foods not included in the list.
4. Weigh out the food articles used in problem No. 2, and apportion them among three meals.