Regularity. Meals should be served promptly at regular hours, and no food taken between meals. If food is taken irregularly, rhythm is disturbed, the digestive fluids are not ready and cannot act efficiently. If food is taken while undigested food remains in the stomach, the work of digestion must begin over again, as the fluids secreted in the early stage of digestion are different from those in the last stages. Thus the food previously taken is kept in the stomach too long; it ferments, too much acid is produced, sour stomach results, the stomach is irritated, the glands are overworked and become exhausted, and the consequence is poor digestion. To do its best work, the stomach requires rest between feedings.
During sleep, the activity of the digestive tract is very slow. Solid food taken less than an hour or two before bedtime is not well digested and is likely to remain in the stomach and ferment; the pressure produces disturbed sleep and “bad dreams”; the stomach is not ready for digesting breakfast; the individual wakens tired, without appetite, and possibly with headache or nausea. Babies, having only milk, can be fed at bedtime. With children two to six years, an hour should intervene between the light supper and sleep; with older children, from two to four hours.
If a child is regularly hungry between meals, the cause may be (a) insufficient quantity at meals; (b) diet not well balanced—frequently insufficient mineral foods; (c) eating too rapidly so that food is not well chewed and therefore not assimilated; (d) too long intervals between meals. If occasionally hungry between meals, light food requiring little digestion should be given, such as fruit juice, ripe fruit, dates, figs, or a glass of milk. Cake, cookies, candies, or other hearty foods upset digestion.
Simplicity. This applies both to the variety served at one meal, to the method of preparation, and to the serving. A maximum of five or six food items at one meal is sufficient, and is more easily digested than a greater number. Foods simply cooked require less work of the digestive organs than do more complex mixtures; at the same time they cultivate simple tastes, with their contentment.
Cheerfulness. Good cheer is the best of appetizers. Professor Pawlow has discovered that the amount and the efficiency of the gastric juice are affected by the anticipation and enjoyment of food, and that the gastric juice thus poured out at the beginning of a meal, which he has called the “appetite juice”, is the most powerful and active. Happiness and laughter (but not silliness or horseplay) should therefore be encouraged at meals.
A child should not be fed when excited, angry, cross, crying, unhappy, or overtired. Under emotional stress no gastric or intestinal juices are formed, and food cannot be digested. When a child is very tired, the system is too exhausted to do the work of digestion, and nitrogenous foods (such as meat or eggs) taken then are positively harmful, as they only decay. If at mealtime a child is cross simply because he is hungry, feeding will help put him in a happy mood, conducive to digestion. Otherwise, it is better to give only a small quantity of easily digested food, such as fruit juice, thin gruel, vegetable broth, toast, milk.
Sufficiency. This applies to the total quantity of energy and fuel foods, or what is technically called caloric sufficiency; and to the quantity and proportions of each of the food elements, technically called a balanced ration. Careful studies of dietetic needs have been made within the last ten years, and the approximate needs and conditions for different ages are now so well defined that adequate feeding need no longer be mere guess-work.
Caloric Sufficiency. A calorie is the measure of a unit of heat as an inch is a measure of a unit of space. One calorie[18] of heat is the amount that will raise the temperature of a pint of water 4° Fahrenheit. The amount of a given food, as of bread, that would furnish this much of heat when digested in the body is a one-calorie portion of bread,—1/10 ounce, or a half-inch cube. The total caloric requirement depends upon the amount of bodily heat and muscular energy needed by an individual. This will depend upon the individual’s (1) weight, (2) age, (3) occupation, (4) health, (5) climate. The amount of outdoor life, clothing, the temperament, height, and personal idiosyncrasies will require individual variations from the average.
Daily Energy Requirements During Growth.
Part of this energy is needed to carry on the vital processes, such as circulation, secretion, digestion; during the waking hours, energy is needed for every muscular action, such as walking, dressing, talking, exercising.