Order of Taking Food.—There has been evolved through experience a rather definite order of taking food, which our knowledge of the process of digestion seems to justify. The heavy foods (proteids for the most part) are eaten first; after which are taken starchy foods and fats; and the meal is finished off with sweetmeats and pastry.[64] The scientific arguments for this order are the following:

1. By receiving the first of the gastric flow the proteids can begin[pg 162] digesting without delay. Since these are the main substances acted on in the stomach, the time required for their digestion is shortened by eating them first.

2. Sugar, being of the nature of predigested starch, quickly gets into the blood and satisfies the relish for food. The result of taking sugar first may be to cause one to eat less than he needs and to diminish the activity of the glands.

3. Fat or grease, if taken first, tends to form a coating over the walls of the stomach and around the material to be digested. This prevents the juices from getting to and mixing with the foods upon which they are to act.

4. Starch following the proteids, for the most part, does not so quickly come in contact with the gastric juice. This enables the ptyalin of the saliva to continue its action for a longer time than if the starch were eaten first.

Liquids during the Meal.—Liquids as ordinarily taken during the meal are objectionable. They tend to diminish the secretion of the saliva and to cause rapid eating. Instead of eating slowly and swallowing the food only so fast as the glands can supply the necessary saliva, the liquid is used to wash the food down. Water or other drinks should be taken after the completion of the meal or when the mouth is completely free from food. Even then it should be taken in small sips. While the taking of a small amount of water in this way does no harm, a large volume has the effect of weakening the gastric juice. Most of the water needed by the body should be taken between meals.

The State of Mind has much to do with the proper digestion of the food. Worry, anger, fear, and other disturbed mental states are known to check the secretion of fluids and to interfere with the digestive processes. While the cultivation of cheerfulness is important for its general hygienic effects, it is of especial value in relation to digestion. Intense emotions, either during or following the[pg 163] meal, should if possible be avoided. The table is no place for settling difficulties or administering rebuke. The conversation, on the other hand, should be elevating and joy giving, thereby inducing a desirable reactionary influence upon the digestive processes.

Care of the Teeth.—The natural teeth are indispensable for the proper mastication of the food. Of especial value are the molars—the teeth that grind the food. The development of the profession of dentistry has made possible the preservation of the teeth, even when naturally poor, as long as one has need of them. To preserve the teeth they must be kept clean. They should be washed at least once a day with a soft-bristled brush, and small particles of food, lodged between them, should be removed with a wooden pick. The biting of hard substances, such as nuts, should be avoided, on account of the danger of breaking the enamel, although the chewing of tough substances is considered beneficial.

Decayed places in the teeth should be promptly filled by the dentist. It is well, even when decayed places are not known to exist, to have the teeth examined occasionally in order to detect such places before they become large. On account of the expense, pain, and inconvenience there is a tendency to put off dental work which one knows ought to be done. Perhaps in no other instance is procrastination so surely punished. The decayed places become larger and new points of decay are started; and the pain, inconvenience, and expense are increased proportionately.

The Natural Appetite should be followed with reference to both the kind and the amount of food eaten. No system of knowledge will ever be devised which can replace the appetite as an aid in the taking of food. It is[pg 164] nature's means of indicating the needs of the body. The natural appetite may be spoiled, however, by overeating and by the use of highly seasoned foods, or by indulging in stimulants during the meal. It is spoiled in children by too free indulgence in sweetmeats. By cultivating the natural appetite and heeding its suggestions, one has at his command an almost infallible guide in the taking of food.