Many factors enter into the food problem as it appears in everyday life. In the same household there are generally persons of different food requirements. The baby cannot be fed like the 15-year old high school girl is fed. The dainty fare which best suits the school teacher is held in scorn by the farm worker whose energy needs are twice as high. To use the same food resources for all and make adjustments which assure for each a palatable, digestible, and adequate diet call for knowledge and skill in the apportionment of the various items on the menu.

Milk is a great protector of the diet in almost every point: of unique importance for calcium, an outstanding source of riboflavin and phosphorus, and a significant source of vitamins A and B. Even in adult life, therefore, a liberal amount of milk should be included at all times, at least a pint a day.

Vegetables and fruits deserve a definite place in the diet because of the mineral salts which they furnish, and also because of their laxative properties. Green vegetables, carrots, tomatoes, potatoes, cabbage and citrus fruits are particularly valuable and should be used frequently.

The amount of eggs, meat and other flesh foods to be used is determined partly by their nutritive value, partly by their flavor and ease of preparation for the table, and partly by their cost. Meats are relatively expensive in comparison with their nutritive return. Eggs give a higher nutritive return than meat, being rich in vitamin A and a good source of vitamin B, D and G, while ordinary muscle meat is a poor source of vitamin A and D and good source of vitamins B & G.

The foods from cereal grains are valuable as sources of energy and protein, and if whole grain or enriched, of iron and vitamins B & G. They are the most economical items in the diet, and the proportion used depends largely upon the amount of money available for food. As much as one half of the total calories of an adult man’s diet may be secured from this group of foods.

Fats and oils, because of their flavor and “staying power” as well as their high content of calories per pound, are important in a good diet. When other sources of vitamin A are limited, it is desirable that much of the fat be butter or fortified oleomargarine unless cod liver oil is used regularly.

Sugars, while adding much to the palatability of the diet, contribute fuel only and must not constitute a high proportion of the total calories or there will be danger of shortage of ash constituents and vitamins, and also danger of digestive disturbances.